{"id":3447,"date":"2025-03-24T08:46:10","date_gmt":"2025-03-23T23:46:10","guid":{"rendered":"https:\/\/dexall.co.jp\/articles\/?p=3447"},"modified":"2025-03-24T08:46:39","modified_gmt":"2025-03-23T23:46:39","slug":"%e3%80%90%e5%ae%8c%e5%85%a8%e8%a7%a3%e8%aa%ac%e3%80%91php-substr%e3%83%9e%e3%82%b9%e3%82%bf%e3%83%bc%e3%82%ac%e3%82%a4%e3%83%89%e3%80%9c%e6%96%87%e5%ad%97%e5%88%97%e6%93%8d%e4%bd%9c%e3%82%92%e5%8a%87","status":"publish","type":"post","link":"https:\/\/dexall.co.jp\/articles\/?p=3447","title":{"rendered":"\u3010\u5b8c\u5168\u89e3\u8aac\u3011PHP substr\u30de\u30b9\u30bf\u30fc\u30ac\u30a4\u30c9\u301c\u6587\u5b57\u5217\u64cd\u4f5c\u3092\u5287\u7684\u306b\u5411\u4e0a\u3055\u305b\u308b7\u3064\u306e\u4f7f\u7528\u6cd5"},"content":{"rendered":"\n<div class=\"toc\"><br \/>\n<b>Warning<\/b>:  Undefined array key \"is_admin\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>116<\/b><br \/>\n<br \/>\n<b>Warning<\/b>:  Undefined array key \"is_category_top\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>121<\/b><br \/>\n<br \/>\n<b>Warning<\/b>:  Undefined array key \"is_top\" in <b>\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/sango-theme\/library\/gutenberg\/dist\/classes\/Toc.php<\/b> on line <b>128<\/b><br \/>\n    <div id=\"toc_container\" class=\"sgb-toc--bullets js-smooth-scroll\" data-dialog-title=\"\u76ee\u6b21\">\n      <p class=\"toc_title\">\u76ee\u6b21 <\/p>\n      <ul class=\"toc_list\">  <li class=\"first\">    <a href=\"#i-0\">\u30a4\u30f3\u30c8\u30ed\u30c0\u30af\u30b7\u30e7\u30f3<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-1\">PHP\u3067\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u91cd\u8981\u6027<\/a>      <\/li>      <li>        <a href=\"#i-2\">substr\u306e\u57fa\u672c\u7684\u306a\u5f79\u5272\u3068\u91cd\u8981\u6027<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-3\">\u3053\u306e\u8a18\u4e8b\u3067\u5b66\u3079\u308b\u3053\u3068<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-4\">PHP substr\u306e\u57fa\u790e\u77e5\u8b58<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-5\">PHP substr\u3068\u306f\u4f55\u304b\uff1f\u57fa\u672c\u69cb\u6587\u3068\u5f79\u5272\u3092\u5fb9\u5e95\u89e3\u8aac<\/a>      <\/li>      <li>        <a href=\"#i-6\">\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u610f\u5473\u3068\u4f7f\u3044\u65b9\u304c\u4e00\u76ee\u3067\u308f\u304b\u308b\u89e3\u8aac<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-10\">\u623b\u308a\u5024\u306e\u8a73\u7d30\u3068null\u5b89\u5168\u6027\u306b\u3064\u3044\u3066<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-13\">PHP substr\u306e\u57fa\u790e\u77e5\u8b58<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-14\">PHP substr\u3068\u306f\u4f55\u304b\uff1f\u57fa\u672c\u69cb\u6587\u3068\u5f79\u5272\u3092\u5fb9\u5e95\u89e3\u8aac<\/a>      <\/li>      <li>        <a href=\"#i-15\">\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u610f\u5473\u3068\u4f7f\u3044\u65b9\u304c\u4e00\u76ee\u3067\u308f\u304b\u308b\u89e3\u8aac<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-19\">\u623b\u308a\u5024\u306e\u8a73\u7d30\u3068null\u5b89\u5168\u6027\u306b\u3064\u3044\u3066<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-22\">\u5b9f\u8df5\u7684\u306aPHP substr\u6d3b\u7528\u6cd5<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-23\">\u6587\u5b57\u5217\u306e\u5148\u982d\u304b\u3089\u6307\u5b9a\u6587\u5b57\u6570\u3092\u53d6\u5f97\u3059\u308b\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-27\">\u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u6307\u5b9a\u6587\u5b57\u6570\u3092\u53d6\u5f97\u3059\u308b\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>      <li>        <a href=\"#i-30\">\u6587\u5b57\u5217\u306e\u4e2d\u9593\u90e8\u5206\u3092\u62bd\u51fa\u3059\u308b\u5b9f\u7528\u4f8b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-34\">\u8ca0\u306e\u6570\u3092\u4f7f\u3063\u305f\u9006\u5f15\u304d\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u6307\u5b9a\u306e\u6d3b\u7528\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-39\">PHP substr\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-40\">\u6761\u4ef6\u5206\u5c90\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\u306b\u3088\u308b\u67d4\u8edf\u306a\u6587\u5b57\u5217\u51e6\u7406<\/a>      <\/li>      <li>        <a href=\"#i-43\">\u30eb\u30fc\u30d7\u51e6\u7406\u3068\u306e\u9023\u643a\u3067\u5b9f\u73fe\u3059\u308b\u9ad8\u5ea6\u306a\u6587\u5b57\u5217\u64cd\u4f5c<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-46\">\u6b63\u898f\u8868\u73fe\u3068\u306e\u4f7f\u3044\u5206\u3051\u3067\u52b9\u7387\u7684\u306a\u30b3\u30fc\u30c9\u3092\u5b9f\u73fe\u3059\u308b\u65b9\u6cd5<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-51\">PHP substr\u306e\u30a8\u30e9\u30fc\u56de\u907f\u3068\u5bfe\u7b56<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-52\">\u3088\u304f\u3042\u308bsubstr\u95a2\u9023\u30a8\u30e9\u30fc\u3068\u30c7\u30d0\u30c3\u30b0\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-55\">\u7a7a\u6587\u5b57\u5217\u3084\u7121\u52b9\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3078\u306e\u5bfe\u5fdc\u7b56<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-58\">\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6700\u9069\u5316\u306e\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-61\">\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u5bfe\u5fdc\u306e\u305f\u3081\u306emb_substr<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-62\">PHP substr\u3068mb_substr\u306e\u9055\u3044\u3068\u4f7f\u3044\u5206\u3051<\/a>      <\/li>      <li>        <a href=\"#i-65\">\u65e5\u672c\u8a9e\u306a\u3069\u306e\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6b63\u3057\u304f\u51e6\u7406\u3059\u308b\u65b9\u6cd5<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-68\">\u6587\u5b57\u30b3\u30fc\u30c9\u3092\u610f\u8b58\u3057\u305f\u5805\u7262\u306a\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-72\">\u5b9f\u52d9\u3067\u4f7f\u3048\u308bPHP substr\u6d3b\u7528\u4f8b7\u9078<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-73\">Web\u30d5\u30a9\u30fc\u30e0\u304b\u3089\u306e\u5165\u529b\u5024\u3092\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-75\">\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u691c\u7d22\u7d50\u679c\u3092\u6700\u9069\u306b\u8868\u793a\u3059\u308b\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>      <li>        <a href=\"#i-77\">API\u30ec\u30b9\u30dd\u30f3\u30b9\u306e\u6587\u5b57\u5217\u3092\u52b9\u7387\u7684\u306b\u52a0\u5de5\u3059\u308b\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-79\">\u30d5\u30a1\u30a4\u30eb\u5165\u51fa\u529b\u306b\u304a\u3051\u308b\u6587\u5b57\u5217\u51e6\u7406\u306e\u5b9f\u88c5\u4f8b<\/a>      <\/li>      <li>        <a href=\"#i-81\">URL\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u89e3\u6790\u3068\u51e6\u7406\u306b\u304a\u3051\u308b\u6d3b\u7528\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-83\">\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u5bfe\u7b56\u3068\u3057\u3066\u306e\u6587\u5b57\u5217\u691c\u8a3c\u3067\u306e\u4f7f\u3044\u65b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-85\">\u30ed\u30b0\u30c7\u30fc\u30bf\u306e\u89e3\u6790\u3068\u52a0\u5de5\u306b\u304a\u3051\u308b\u5b9f\u7528\u30d1\u30bf\u30fc\u30f3<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-87\">\u95a2\u9023\u3059\u308b\u6587\u5b57\u5217\u95a2\u6570\u3068\u306e\u9023\u643a<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-88\">strpos\u3068substr\u3092\u7d44\u307f\u5408\u308f\u305b\u305f\u9ad8\u5ea6\u306a\u6587\u5b57\u5217\u64cd\u4f5c<\/a>      <\/li>      <li>        <a href=\"#i-91\">str_replace\u3068\u306e\u4f7f\u3044\u5206\u3051\u3067\u5b9f\u73fe\u3059\u308b\u67d4\u8edf\u306a\u30c6\u30ad\u30b9\u30c8\u52a0\u5de5<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-94\">explode\u3068substr\u306e\u4f7f\u3044\u5206\u3051\u3068\u7d44\u307f\u5408\u308f\u305b\u6226\u7565<\/a>      <\/li>    <\/ul>  <\/li>  <li class=\"last\">    <a href=\"#i-98\">\u307e\u3068\u3081<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-99\">\u8a18\u4e8b\u3067\u5b66\u3093\u3060\u5185\u5bb9\u306e\u5fa9\u7fd2\u3068\u307e\u3068\u3081<\/a>      <\/li>      <li>        <a href=\"#i-100\">PHP substr\u30de\u30b9\u30bf\u30fc\u5f8c\u306e\u6b21\u306e\u30b9\u30c6\u30c3\u30d7<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-101\">\u6587\u5b57\u5217\u51e6\u7406\u30b9\u30ad\u30eb\u5411\u4e0a\u306e\u305f\u3081\u306e\u5b9f\u8df5\u7684\u30a2\u30c9\u30d0\u30a4\u30b9<\/a>      <\/li>    <\/ul>  <\/li><\/ul>\n      <a href=\"#\" class=\"sgb-toc-button js-toc-button\" rel=\"nofollow\" data-open-dialog=\"true\"><i class=\"fa fa-list\"><\/i><span class=\"sgb-toc-button__text\">\u76ee\u6b21\u3078<\/span><\/a>\n    <\/div><\/div><h2 class=\"wp-block-heading\" id=\"i-0\">\u30a4\u30f3\u30c8\u30ed\u30c0\u30af\u30b7\u30e7\u30f3<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-1\">PHP\u3067\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u91cd\u8981\u6027<\/h3>\n\n\n\n<p>Web\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u958b\u767a\u306b\u304a\u3044\u3066\u3001\u6587\u5b57\u5217\u64cd\u4f5c\u306f\u307b\u307c\u3059\u3079\u3066\u306e\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u5fc5\u8981\u3068\u306a\u308b\u57fa\u672c\u7684\u304b\u3064\u91cd\u8981\u306a\u30b9\u30ad\u30eb\u3067\u3059\u3002PHP\u306e\u5834\u5408\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b7\u30fc\u30f3\u3067\u6587\u5b57\u5217\u51e6\u7406\u304c\u4e0d\u53ef\u6b20\u3068\u306a\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30fc\u30b6\u30fc\u304b\u3089\u306e\u30d5\u30a9\u30fc\u30e0\u5165\u529b\u30c7\u30fc\u30bf\u306e\u691c\u8a3c\u3084\u6574\u5f62<\/li>\n\n\n\n<li>URL\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u89e3\u6790\u3068\u51e6\u7406<\/li>\n\n\n\n<li>\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u30af\u30a8\u30ea\u7d50\u679c\u306e\u52a0\u5de5\u3068\u8868\u793a<\/li>\n\n\n\n<li>API\u30ec\u30b9\u30dd\u30f3\u30b9\u30c7\u30fc\u30bf\u306e\u51e6\u7406\u3068\u5909\u63db<\/li>\n\n\n\n<li>\u30ed\u30b0\u30d5\u30a1\u30a4\u30eb\u306e\u751f\u6210\u3068\u89e3\u6790<\/li>\n<\/ul>\n\n\n\n<p>\u52b9\u7387\u7684\u306a\u6587\u5b57\u5217\u64cd\u4f5c\u306f\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u76f4\u7d50\u3059\u308b\u3060\u3051\u3067\u306a\u304f\u3001\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u5bfe\u7b56\u3068\u3057\u3066\u3082\u91cd\u8981\u306a\u5f79\u5272\u3092\u679c\u305f\u3057\u307e\u3059\u3002\u305f\u3068\u3048\u3070\u30af\u30ed\u30b9\u30b5\u30a4\u30c8\u30b9\u30af\u30ea\u30d7\u30c6\u30a3\u30f3\u30b0(XSS)\u5bfe\u7b56\u3067\u306f\u3001\u30e6\u30fc\u30b6\u30fc\u5165\u529b\u3092\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u6587\u5b57\u5217\u64cd\u4f5c\u304c\u5fc5\u9808\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-2\">substr\u306e\u57fa\u672c\u7684\u306a\u5f79\u5272\u3068\u91cd\u8981\u6027<\/h3>\n\n\n\n<p>PHP\u306e<code>substr<\/code>\u95a2\u6570\u306f\u3001\u6587\u5b57\u5217\u304b\u3089\u6307\u5b9a\u3057\u305f\u90e8\u5206\u6587\u5b57\u5217\u3092\u62bd\u51fa\u3059\u308b\u305f\u3081\u306e\u7d44\u307f\u8fbc\u307f\u95a2\u6570\u3067\u3059\u3002\u57fa\u672c\u7684\u306a\u69cb\u6587\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">string substr(string $string, int $offset, ?int $length = null)\n<\/pre>\n\n\n\n<p>\u4e00\u898b\u30b7\u30f3\u30d7\u30eb\u306a\u3053\u306e\u95a2\u6570\u3067\u3059\u304c\u3001PHP\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u958b\u767a\u3067\u306f\u975e\u5e38\u306b\u9ad8\u983b\u5ea6\u3067\u4f7f\u7528\u3055\u308c\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u91cd\u8981\u6027\u3092\u6301\u3061\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8907\u96d1\u306a\u6587\u5b57\u5217\u51e6\u7406\u306e\u57fa\u76e4\u3068\u306a\u308b\u57fa\u672c\u64cd\u4f5c<\/li>\n\n\n\n<li>\u4ed6\u306e\u6587\u5b57\u5217\u95a2\u6570\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u5f37\u529b\u306a\u51e6\u7406\u304c\u53ef\u80fd<\/li>\n\n\n\n<li>\u30cd\u30a4\u30c6\u30a3\u30d6\u95a2\u6570\u3068\u3057\u3066\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u6700\u9069\u5316\u3055\u308c\u3066\u3044\u308b<\/li>\n\n\n\n<li>\u6587\u5b57\u5217\u306e\u691c\u8a3c\u3084\u52a0\u5de5\u306b\u304a\u3051\u308b\u4e2d\u5fc3\u7684\u306a\u5f79\u5272\u3092\u62c5\u3046<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-3\">\u3053\u306e\u8a18\u4e8b\u3067\u5b66\u3079\u308b\u3053\u3068<\/h3>\n\n\n\n<p>\u672c\u8a18\u4e8b\u3067\u306f\u3001PHP\u306e<code>substr<\/code>\u95a2\u6570\u3092\u5fb9\u5e95\u7684\u306b\u89e3\u8aac\u3057\u3001\u6587\u5b57\u5217\u64cd\u4f5c\u30b9\u30ad\u30eb\u3092\u5411\u4e0a\u3055\u305b\u308b\u305f\u3081\u306e\u77e5\u8b58\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002\u5177\u4f53\u7684\u306b\u306f\u4ee5\u4e0b\u306e\u5185\u5bb9\u3092\u5b66\u3076\u3053\u3068\u304c\u3067\u304d\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>substr<\/code>\u306e\u57fa\u672c\u69cb\u6587\u3068\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u610f\u5473<\/li>\n\n\n\n<li>\u5b9f\u8df5\u7684\u306a\u6d3b\u7528\u6cd5\u3068\u5177\u4f53\u7684\u306a\u30b3\u30fc\u30c9\u4f8b<\/li>\n\n\n\n<li>\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af\u3068\u4ed6\u306e\u51e6\u7406\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\u65b9<\/li>\n\n\n\n<li>\u4e00\u822c\u7684\u306a\u30a8\u30e9\u30fc\u306e\u56de\u907f\u65b9\u6cd5\u3068\u5bfe\u7b56<\/li>\n\n\n\n<li>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\uff08\u65e5\u672c\u8a9e\u306a\u3069\uff09\u3092\u6271\u3046\u969b\u306e\u6ce8\u610f\u70b9<\/li>\n\n\n\n<li>\u5b9f\u52d9\u3067\u5373\u5f79\u7acb\u30647\u3064\u306e\u6d3b\u7528\u30d1\u30bf\u30fc\u30f3<\/li>\n\n\n\n<li>\u95a2\u9023\u3059\u308b\u6587\u5b57\u5217\u95a2\u6570\u3068\u306e\u52b9\u679c\u7684\u306a\u7d44\u307f\u5408\u308f\u305b\u65b9<\/li>\n<\/ul>\n\n\n\n<p>PHP\u3092\u5b66\u3073\u59cb\u3081\u305f\u3070\u304b\u308a\u306e\u521d\u5fc3\u8005\u304b\u3089\u3001\u30b3\u30fc\u30c9\u306e\u6700\u9069\u5316\u3092\u56f3\u308a\u305f\u3044\u4e2d\u7d1a\u8005\u307e\u3067\u3001\u5e45\u5e83\u3044\u958b\u767a\u8005\u306b\u3068\u3063\u3066\u4fa1\u5024\u3042\u308b\u60c5\u5831\u3092\u7db2\u7f85\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u306e\u8a18\u4e8b\u3092\u901a\u3058\u3066\u3001\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u57fa\u672c\u3068\u306a\u308b<code>substr<\/code>\u3092\u30de\u30b9\u30bf\u30fc\u3057\u3001\u3088\u308a\u5805\u7262\u3067\u52b9\u7387\u7684\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-4\">PHP substr\u306e\u57fa\u790e\u77e5\u8b58<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-5\">PHP substr\u3068\u306f\u4f55\u304b\uff1f\u57fa\u672c\u69cb\u6587\u3068\u5f79\u5272\u3092\u5fb9\u5e95\u89e3\u8aac<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306f\u3001PHP\u8a00\u8a9e\u306b\u7d44\u307f\u8fbc\u307e\u308c\u305f\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u57fa\u672c\u95a2\u6570\u306e\u4e00\u3064\u3067\u3001\u6307\u5b9a\u3057\u305f\u6587\u5b57\u5217\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\uff08substring\uff09\u3092\u62bd\u51fa\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3057\u307e\u3059\u3002PHP 4\u304b\u3089\u5b58\u5728\u3059\u308b\u6b74\u53f2\u3042\u308b\u95a2\u6570\u3067\u3042\u308a\u3001\u73fe\u5728\u306ePHP 8\u3067\u3082\u5f15\u304d\u7d9a\u304d\u91cd\u8981\u306a\u5f79\u5272\u3092\u62c5\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u57fa\u672c\u69cb\u6587\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">string substr(string $string, int $offset, ?int $length = null)\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306e\u4e3b\u306a\u5f79\u5272\u306f\u3001\u6587\u5b57\u5217\u306e\u7279\u5b9a\u90e8\u5206\u3092\u53d6\u308a\u51fa\u3059\u3053\u3068\u3067\u3001\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5834\u9762\u3067\u6d3b\u8e8d\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30fc\u30b6\u30fc\u540d\u3084ID\u306e\u4e00\u90e8\u3092\u8868\u793a\u3059\u308b\uff08\u30d7\u30e9\u30a4\u30d0\u30b7\u30fc\u4fdd\u8b77\uff09<\/li>\n\n\n\n<li>\u9577\u3059\u304e\u308b\u30c6\u30ad\u30b9\u30c8\u3092\u5207\u308a\u8a70\u3081\u3066\u300c\u7d9a\u304d\u3092\u8aad\u3080\u300d\u6a5f\u80fd\u3092\u5b9f\u88c5<\/li>\n\n\n\n<li>\u30d5\u30a1\u30a4\u30eb\u540d\u304b\u3089\u62e1\u5f35\u5b50\u3092\u62bd\u51fa\u3059\u308b<\/li>\n\n\n\n<li>\u65e5\u4ed8\u3084\u6642\u523b\u306e\u4e00\u90e8\u3092\u53d6\u308a\u51fa\u3059<\/li>\n<\/ul>\n\n\n\n<p>\u7c21\u5358\u306a\u4f7f\u7528\u4f8b\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$text = \"Hello, World!\";\necho substr($text, 0, 5); \/\/ \u51fa\u529b: Hello\necho substr($text, 7);    \/\/ \u51fa\u529b: World!\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-6\">\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u610f\u5473\u3068\u4f7f\u3044\u65b9\u304c\u4e00\u76ee\u3067\u308f\u304b\u308b\u89e3\u8aac<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306e\u5404\u30d1\u30e9\u30e1\u30fc\u30bf\u306b\u306f\u660e\u78ba\u306a\u5f79\u5272\u304c\u3042\u308a\u307e\u3059\u3002\u6b63\u3057\u304f\u7406\u89e3\u3059\u308b\u3053\u3068\u3067\u3001\u67d4\u8edf\u306a\u6587\u5b57\u5217\u64cd\u4f5c\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-7\">1. $string\uff08\u5fc5\u9808\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b: string<\/li>\n\n\n\n<li>\u5f79\u5272: \u90e8\u5206\u6587\u5b57\u5217\u3092\u62bd\u51fa\u3059\u308b\u5143\u3068\u306a\u308b\u6587\u5b57\u5217<\/li>\n\n\n\n<li>\u6ce8\u610f\u70b9: \u3053\u306e\u5024\u304c\u7a7a\u6587\u5b57\u5217\u306e\u5834\u5408\u3001\u7d50\u679c\u3082\u7a7a\u6587\u5b57\u5217\u306b\u306a\u308a\u307e\u3059<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-8\">2. $offset\uff08\u5fc5\u9808\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b: int<\/li>\n\n\n\n<li>\u5f79\u5272: \u62bd\u51fa\u3092\u958b\u59cb\u3059\u308b\u4f4d\u7f6e\uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\uff09<\/li>\n\n\n\n<li>\u7279\u5fb4:\n<ul class=\"wp-block-list\">\n<li>0\u304b\u3089\u59cb\u307e\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\uff08\u6700\u521d\u306e\u6587\u5b57\u306f0\uff09<\/li>\n\n\n\n<li>\u6b63\u306e\u5024: \u6587\u5b57\u5217\u306e\u5148\u982d\u304b\u3089\u30ab\u30a6\u30f3\u30c8<\/li>\n\n\n\n<li>\u8ca0\u306e\u5024: \u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u30ab\u30a6\u30f3\u30c8<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n<div id=\"id-2a6dba9e-c2fd-4da5-bbf1-186a1be377e4\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>$offset\u5024<\/th><th>\u610f\u5473<\/th><\/tr><\/thead><tbody><tr><td>0<\/td><td>\u6587\u5b57\u5217\u306e\u5148\u982d\u304b\u3089<\/td><\/tr><tr><td>5<\/td><td>\u5148\u982d\u304b\u30896\u756a\u76ee\u306e\u6587\u5b57\u304b\u3089<\/td><\/tr><tr><td>-1<\/td><td>\u6587\u5b57\u5217\u306e\u6700\u5f8c\u306e\u6587\u5b57\u304b\u3089<\/td><\/tr><tr><td>-3<\/td><td>\u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u30893\u756a\u76ee\u306e\u6587\u5b57\u304b\u3089<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h4 class=\"wp-block-heading\" id=\"i-9\">3. $length\uff08\u4efb\u610f\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b: ?int\uff08PHP 8\u4ee5\u964d\u306fnull\u8a31\u5bb9\uff09<\/li>\n\n\n\n<li>\u5f79\u5272: \u62bd\u51fa\u3059\u308b\u6587\u5b57\u6570<\/li>\n\n\n\n<li>\u7279\u5fb4:\n<ul class=\"wp-block-list\">\n<li>\u7701\u7565\u307e\u305f\u306f null: \u6587\u5b57\u5217\u306e\u672b\u5c3e\u307e\u3067\u62bd\u51fa<\/li>\n\n\n\n<li>\u6b63\u306e\u5024: \u6307\u5b9a\u3057\u305f\u6587\u5b57\u6570\u3060\u3051\u62bd\u51fa<\/li>\n\n\n\n<li>\u8ca0\u306e\u5024: \u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u6307\u5b9a\u3057\u305f\u6587\u5b57\u6570\u3092\u9664\u3044\u305f\u7bc4\u56f2\u3092\u62bd\u51fa<\/li>\n\n\n\n<li>0: \u7a7a\u6587\u5b57\u5217\u3092\u8fd4\u3059<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u6b21\u306e\u4f8b\u3067\u5404\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u4f7f\u3044\u65b9\u3092\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$str = \"abcdefghijklmn\";\n\n\/\/ \u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\necho substr($str, 3, 4);     \/\/ \u51fa\u529b: \"defg\" \uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b93\u304b\u30894\u6587\u5b57\uff09\n\n\/\/ \u8ca0\u306e\u30aa\u30d5\u30bb\u30c3\u30c8\uff08\u672b\u5c3e\u304b\u3089\u306e\u30ab\u30a6\u30f3\u30c8\uff09\necho substr($str, -5, 3);    \/\/ \u51fa\u529b: \"jkl\" \uff08\u672b\u5c3e\u304b\u30895\u756a\u76ee\u306e\u6587\u5b57\u304b\u30893\u6587\u5b57\uff09\n\n\/\/ \u8ca0\u306e\u9577\u3055\uff08\u672b\u5c3e\u304b\u3089\u6307\u5b9a\u6587\u5b57\u6570\u3092\u9664\u304f\uff09\necho substr($str, 2, -4);    \/\/ \u51fa\u529b: \"cdefghij\" \uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b92\u304b\u3089\u59cb\u3081\u3066\u3001\u672b\u5c3e\u306e4\u6587\u5b57\u3092\u9664\u304f\uff09\n\n\/\/ length\u3092\u7701\u7565\u3057\u305f\u5834\u5408\uff08\u672b\u5c3e\u307e\u3067\uff09\necho substr($str, 8);        \/\/ \u51fa\u529b: \"ijklmn\" \uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b98\u304b\u3089\u672b\u5c3e\u307e\u3067\uff09\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-10\">\u623b\u308a\u5024\u306e\u8a73\u7d30\u3068null\u5b89\u5168\u6027\u306b\u3064\u3044\u3066<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306e\u623b\u308a\u5024\u306f\u5e38\u306b\u6587\u5b57\u5217\u578b\uff08string\uff09\u3067\u3059\u3002\u305f\u3060\u3057\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30a8\u30c3\u30b8\u30b1\u30fc\u30b9\u306b\u3064\u3044\u3066\u7406\u89e3\u3057\u3066\u304a\u304f\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-11\">\u623b\u308a\u5024\u306e\u30a8\u30c3\u30b8\u30b1\u30fc\u30b9<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7a7a\u6587\u5b57\u5217\u304c\u8fd4\u3055\u308c\u308b\u30b1\u30fc\u30b9<\/strong>:\n<ul class=\"wp-block-list\">\n<li>$string\u304c\u7a7a\u6587\u5b57\u5217\u306e\u5834\u5408<\/li>\n\n\n\n<li>$offset\u304c\u6587\u5b57\u5217\u9577\u4ee5\u4e0a\u306e\u5834\u5408<\/li>\n\n\n\n<li>$length\u304c0\u306e\u5834\u5408<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u90e8\u5206\u7684\u306a\u7d50\u679c\u304c\u8fd4\u3055\u308c\u308b\u30b1\u30fc\u30b9<\/strong>:\n<ul class=\"wp-block-list\">\n<li>$offset + $length\u304c\u6587\u5b57\u5217\u9577\u3092\u8d85\u3048\u308b\u5834\u5408\u3001\u53ef\u80fd\u306a\u9650\u308a\u306e\u6587\u5b57\u304c\u8fd4\u3055\u308c\u308b<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$str = \"PHP\";\necho substr($str, 10);       \/\/ \u51fa\u529b: \"\" \uff08\u6587\u5b57\u5217\u9577\u3092\u8d85\u3048\u308b\u30aa\u30d5\u30bb\u30c3\u30c8\uff09\necho substr($str, 0, 0);     \/\/ \u51fa\u529b: \"\" \uff08\u9577\u3055\u304c0\uff09\necho substr($str, 1, 10);    \/\/ \u51fa\u529b: \"HP\" \uff08\u9577\u3055\u304c\u7bc4\u56f2\u5916\u3060\u304c\u3001\u53ef\u80fd\u306a\u9650\u308a\u53d6\u5f97\uff09\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-12\">PHP 8\u3067\u306e\u5909\u66f4\u70b9\u3068null\u5b89\u5168\u6027<\/h4>\n\n\n\n<p>PHP 8\u3067\u306f\u3001<code>substr<\/code>\u95a2\u6570\u306b\u95a2\u3057\u3066\u4ee5\u4e0b\u306e\u5909\u66f4\u304c\u52a0\u3048\u3089\u308c\u307e\u3057\u305f\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u578b\u5ba3\u8a00\u306e\u6539\u5584<\/strong>: $length\u30d1\u30e9\u30e1\u30fc\u30bf\u306b\u660e\u793a\u7684\u306b<code>?int<\/code>\uff08null\u8a31\u5bb9\u6574\u6570\u578b\uff09\u306e\u578b\u30d2\u30f3\u30c8\u304c\u8ffd\u52a0\u3055\u308c\u3001\u3088\u308a\u578b\u5b89\u5168\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/li>\n\n\n\n<li><strong>\u4e00\u8cab\u6027\u306e\u3042\u308b\u30a8\u30e9\u30fc\u51e6\u7406<\/strong>: PHP 7\u307e\u3067\u306f\u4e00\u90e8\u306e\u30a8\u30e9\u30fc\u6761\u4ef6\u3067false\u3092\u8fd4\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3057\u305f\u304c\u3001PHP 8\u304b\u3089\u306f\u3059\u3079\u3066\u306e\u30a8\u30e9\u30fc\u30b1\u30fc\u30b9\u3067\u7a7a\u6587\u5b57\u5217\u3092\u8fd4\u3059\u3088\u3046\u306b\u7d71\u4e00\u3055\u308c\u307e\u3057\u305f\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u623b\u308a\u5024\u306e\u578b\u306e\u4e00\u8cab\u6027\u304c\u5411\u4e0a\u3057\u3066\u3044\u307e\u3059\u3002<\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ PHP 8\u3067\u306e\u578b\u5ba3\u8a00\n\/\/ function substr(string $string, int $offset, ?int $length = null): string\n\n\/\/ \u660e\u793a\u7684\u306bnull\u3092\u6e21\u3059\u3053\u3068\u304c\u3067\u304d\u308b\uff08PHP 8\u4ee5\u964d\uff09\n$str = \"example\";\n$result = substr($str, 0, null); \/\/ $str\u5168\u4f53\u3092\u53d6\u5f97\uff08\"example\"\uff09\n<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u57fa\u790e\u77e5\u8b58\u3092\u62bc\u3055\u3048\u308b\u3053\u3068\u3067\u3001<code>substr<\/code>\u95a2\u6570\u3092\u69d8\u3005\u306a\u72b6\u6cc1\u3067\u9069\u5207\u306b\u6d3b\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3055\u3089\u306b\u5b9f\u8df5\u7684\u306a\u6d3b\u7528\u6cd5\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-13\">PHP substr\u306e\u57fa\u790e\u77e5\u8b58<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-14\">PHP substr\u3068\u306f\u4f55\u304b\uff1f\u57fa\u672c\u69cb\u6587\u3068\u5f79\u5272\u3092\u5fb9\u5e95\u89e3\u8aac<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306f\u3001PHP\u8a00\u8a9e\u306b\u7d44\u307f\u8fbc\u307e\u308c\u305f\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u57fa\u672c\u95a2\u6570\u306e\u4e00\u3064\u3067\u3001\u6307\u5b9a\u3057\u305f\u6587\u5b57\u5217\u304b\u3089\u90e8\u5206\u6587\u5b57\u5217\uff08substring\uff09\u3092\u62bd\u51fa\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3057\u307e\u3059\u3002PHP 4\u304b\u3089\u5b58\u5728\u3059\u308b\u6b74\u53f2\u3042\u308b\u95a2\u6570\u3067\u3042\u308a\u3001\u73fe\u5728\u306ePHP 8\u3067\u3082\u5f15\u304d\u7d9a\u304d\u91cd\u8981\u306a\u5f79\u5272\u3092\u62c5\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u57fa\u672c\u69cb\u6587\u306f\u6b21\u306e\u3068\u304a\u308a\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">string substr(string $string, int $offset, ?int $length = null)\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306e\u4e3b\u306a\u5f79\u5272\u306f\u3001\u6587\u5b57\u5217\u306e\u7279\u5b9a\u90e8\u5206\u3092\u53d6\u308a\u51fa\u3059\u3053\u3068\u3067\u3001\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5834\u9762\u3067\u6d3b\u8e8d\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e6\u30fc\u30b6\u30fc\u540d\u3084ID\u306e\u4e00\u90e8\u3092\u8868\u793a\u3059\u308b\uff08\u30d7\u30e9\u30a4\u30d0\u30b7\u30fc\u4fdd\u8b77\uff09<\/li>\n\n\n\n<li>\u9577\u3059\u304e\u308b\u30c6\u30ad\u30b9\u30c8\u3092\u5207\u308a\u8a70\u3081\u3066\u300c\u7d9a\u304d\u3092\u8aad\u3080\u300d\u6a5f\u80fd\u3092\u5b9f\u88c5<\/li>\n\n\n\n<li>\u30d5\u30a1\u30a4\u30eb\u540d\u304b\u3089\u62e1\u5f35\u5b50\u3092\u62bd\u51fa\u3059\u308b<\/li>\n\n\n\n<li>\u65e5\u4ed8\u3084\u6642\u523b\u306e\u4e00\u90e8\u3092\u53d6\u308a\u51fa\u3059<\/li>\n<\/ul>\n\n\n\n<p>\u7c21\u5358\u306a\u4f7f\u7528\u4f8b\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$text = \"Hello, World!\";\necho substr($text, 0, 5); \/\/ \u51fa\u529b: Hello\necho substr($text, 7);    \/\/ \u51fa\u529b: World!\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-15\">\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u610f\u5473\u3068\u4f7f\u3044\u65b9\u304c\u4e00\u76ee\u3067\u308f\u304b\u308b\u89e3\u8aac<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306e\u5404\u30d1\u30e9\u30e1\u30fc\u30bf\u306b\u306f\u660e\u78ba\u306a\u5f79\u5272\u304c\u3042\u308a\u307e\u3059\u3002\u6b63\u3057\u304f\u7406\u89e3\u3059\u308b\u3053\u3068\u3067\u3001\u67d4\u8edf\u306a\u6587\u5b57\u5217\u64cd\u4f5c\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-16\">1. $string\uff08\u5fc5\u9808\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b: string<\/li>\n\n\n\n<li>\u5f79\u5272: \u90e8\u5206\u6587\u5b57\u5217\u3092\u62bd\u51fa\u3059\u308b\u5143\u3068\u306a\u308b\u6587\u5b57\u5217<\/li>\n\n\n\n<li>\u6ce8\u610f\u70b9: \u3053\u306e\u5024\u304c\u7a7a\u6587\u5b57\u5217\u306e\u5834\u5408\u3001\u7d50\u679c\u3082\u7a7a\u6587\u5b57\u5217\u306b\u306a\u308a\u307e\u3059<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-17\">2. $offset\uff08\u5fc5\u9808\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b: int<\/li>\n\n\n\n<li>\u5f79\u5272: \u62bd\u51fa\u3092\u958b\u59cb\u3059\u308b\u4f4d\u7f6e\uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\uff09<\/li>\n\n\n\n<li>\u7279\u5fb4:\n<ul class=\"wp-block-list\">\n<li>0\u304b\u3089\u59cb\u307e\u308b\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\uff08\u6700\u521d\u306e\u6587\u5b57\u306f0\uff09<\/li>\n\n\n\n<li>\u6b63\u306e\u5024: \u6587\u5b57\u5217\u306e\u5148\u982d\u304b\u3089\u30ab\u30a6\u30f3\u30c8<\/li>\n\n\n\n<li>\u8ca0\u306e\u5024: \u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u30ab\u30a6\u30f3\u30c8<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n<div id=\"id-e405c229-4a12-4026-8c1f-11060bae56e0\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>$offset\u5024<\/th><th>\u610f\u5473<\/th><\/tr><\/thead><tbody><tr><td>0<\/td><td>\u6587\u5b57\u5217\u306e\u5148\u982d\u304b\u3089<\/td><\/tr><tr><td>5<\/td><td>\u5148\u982d\u304b\u30896\u756a\u76ee\u306e\u6587\u5b57\u304b\u3089<\/td><\/tr><tr><td>-1<\/td><td>\u6587\u5b57\u5217\u306e\u6700\u5f8c\u306e\u6587\u5b57\u304b\u3089<\/td><\/tr><tr><td>-3<\/td><td>\u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u30893\u756a\u76ee\u306e\u6587\u5b57\u304b\u3089<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h4 class=\"wp-block-heading\" id=\"i-18\">3. $length\uff08\u4efb\u610f\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u578b: ?int\uff08PHP 8\u4ee5\u964d\u306fnull\u8a31\u5bb9\uff09<\/li>\n\n\n\n<li>\u5f79\u5272: \u62bd\u51fa\u3059\u308b\u6587\u5b57\u6570<\/li>\n\n\n\n<li>\u7279\u5fb4:\n<ul class=\"wp-block-list\">\n<li>\u7701\u7565\u307e\u305f\u306f null: \u6587\u5b57\u5217\u306e\u672b\u5c3e\u307e\u3067\u62bd\u51fa<\/li>\n\n\n\n<li>\u6b63\u306e\u5024: \u6307\u5b9a\u3057\u305f\u6587\u5b57\u6570\u3060\u3051\u62bd\u51fa<\/li>\n\n\n\n<li>\u8ca0\u306e\u5024: \u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u6307\u5b9a\u3057\u305f\u6587\u5b57\u6570\u3092\u9664\u3044\u305f\u7bc4\u56f2\u3092\u62bd\u51fa<\/li>\n\n\n\n<li>0: \u7a7a\u6587\u5b57\u5217\u3092\u8fd4\u3059<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\u6b21\u306e\u4f8b\u3067\u5404\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u4f7f\u3044\u65b9\u3092\u78ba\u8a8d\u3057\u307e\u3057\u3087\u3046\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$str = \"abcdefghijklmn\";\n\n\/\/ \u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\necho substr($str, 3, 4);     \/\/ \u51fa\u529b: \"defg\" \uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b93\u304b\u30894\u6587\u5b57\uff09\n\n\/\/ \u8ca0\u306e\u30aa\u30d5\u30bb\u30c3\u30c8\uff08\u672b\u5c3e\u304b\u3089\u306e\u30ab\u30a6\u30f3\u30c8\uff09\necho substr($str, -5, 3);    \/\/ \u51fa\u529b: \"jkl\" \uff08\u672b\u5c3e\u304b\u30895\u756a\u76ee\u306e\u6587\u5b57\u304b\u30893\u6587\u5b57\uff09\n\n\/\/ \u8ca0\u306e\u9577\u3055\uff08\u672b\u5c3e\u304b\u3089\u6307\u5b9a\u6587\u5b57\u6570\u3092\u9664\u304f\uff09\necho substr($str, 2, -4);    \/\/ \u51fa\u529b: \"cdefghij\" \uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b92\u304b\u3089\u59cb\u3081\u3066\u3001\u672b\u5c3e\u306e4\u6587\u5b57\u3092\u9664\u304f\uff09\n\n\/\/ length\u3092\u7701\u7565\u3057\u305f\u5834\u5408\uff08\u672b\u5c3e\u307e\u3067\uff09\necho substr($str, 8);        \/\/ \u51fa\u529b: \"ijklmn\" \uff08\u30a4\u30f3\u30c7\u30c3\u30af\u30b98\u304b\u3089\u672b\u5c3e\u307e\u3067\uff09\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-19\">\u623b\u308a\u5024\u306e\u8a73\u7d30\u3068null\u5b89\u5168\u6027\u306b\u3064\u3044\u3066<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306e\u623b\u308a\u5024\u306f\u5e38\u306b\u6587\u5b57\u5217\u578b\uff08string\uff09\u3067\u3059\u3002\u305f\u3060\u3057\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30a8\u30c3\u30b8\u30b1\u30fc\u30b9\u306b\u3064\u3044\u3066\u7406\u89e3\u3057\u3066\u304a\u304f\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\uff1a<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-20\">\u623b\u308a\u5024\u306e\u30a8\u30c3\u30b8\u30b1\u30fc\u30b9<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7a7a\u6587\u5b57\u5217\u304c\u8fd4\u3055\u308c\u308b\u30b1\u30fc\u30b9<\/strong>:\n<ul class=\"wp-block-list\">\n<li>$string\u304c\u7a7a\u6587\u5b57\u5217\u306e\u5834\u5408<\/li>\n\n\n\n<li>$offset\u304c\u6587\u5b57\u5217\u9577\u4ee5\u4e0a\u306e\u5834\u5408<\/li>\n\n\n\n<li>$length\u304c0\u306e\u5834\u5408<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u90e8\u5206\u7684\u306a\u7d50\u679c\u304c\u8fd4\u3055\u308c\u308b\u30b1\u30fc\u30b9<\/strong>:\n<ul class=\"wp-block-list\">\n<li>$offset + $length\u304c\u6587\u5b57\u5217\u9577\u3092\u8d85\u3048\u308b\u5834\u5408\u3001\u53ef\u80fd\u306a\u9650\u308a\u306e\u6587\u5b57\u304c\u8fd4\u3055\u308c\u308b<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$str = \"PHP\";\necho substr($str, 10);       \/\/ \u51fa\u529b: \"\" \uff08\u6587\u5b57\u5217\u9577\u3092\u8d85\u3048\u308b\u30aa\u30d5\u30bb\u30c3\u30c8\uff09\necho substr($str, 0, 0);     \/\/ \u51fa\u529b: \"\" \uff08\u9577\u3055\u304c0\uff09\necho substr($str, 1, 10);    \/\/ \u51fa\u529b: \"HP\" \uff08\u9577\u3055\u304c\u7bc4\u56f2\u5916\u3060\u304c\u3001\u53ef\u80fd\u306a\u9650\u308a\u53d6\u5f97\uff09\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-21\">PHP 8\u3067\u306e\u5909\u66f4\u70b9\u3068null\u5b89\u5168\u6027<\/h4>\n\n\n\n<p>PHP 8\u3067\u306f\u3001<code>substr<\/code>\u95a2\u6570\u306b\u95a2\u3057\u3066\u4ee5\u4e0b\u306e\u5909\u66f4\u304c\u52a0\u3048\u3089\u308c\u307e\u3057\u305f\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u578b\u5ba3\u8a00\u306e\u6539\u5584<\/strong>: $length\u30d1\u30e9\u30e1\u30fc\u30bf\u306b\u660e\u793a\u7684\u306b<code>?int<\/code>\uff08null\u8a31\u5bb9\u6574\u6570\u578b\uff09\u306e\u578b\u30d2\u30f3\u30c8\u304c\u8ffd\u52a0\u3055\u308c\u3001\u3088\u308a\u578b\u5b89\u5168\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/li>\n\n\n\n<li><strong>\u4e00\u8cab\u6027\u306e\u3042\u308b\u30a8\u30e9\u30fc\u51e6\u7406<\/strong>: PHP 7\u307e\u3067\u306f\u4e00\u90e8\u306e\u30a8\u30e9\u30fc\u6761\u4ef6\u3067false\u3092\u8fd4\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3057\u305f\u304c\u3001PHP 8\u304b\u3089\u306f\u3059\u3079\u3066\u306e\u30a8\u30e9\u30fc\u30b1\u30fc\u30b9\u3067\u7a7a\u6587\u5b57\u5217\u3092\u8fd4\u3059\u3088\u3046\u306b\u7d71\u4e00\u3055\u308c\u307e\u3057\u305f\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u623b\u308a\u5024\u306e\u578b\u306e\u4e00\u8cab\u6027\u304c\u5411\u4e0a\u3057\u3066\u3044\u307e\u3059\u3002<\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ PHP 8\u3067\u306e\u578b\u5ba3\u8a00\n\/\/ function substr(string $string, int $offset, ?int $length = null): string\n\n\/\/ \u660e\u793a\u7684\u306bnull\u3092\u6e21\u3059\u3053\u3068\u304c\u3067\u304d\u308b\uff08PHP 8\u4ee5\u964d\uff09\n$str = \"example\";\n$result = substr($str, 0, null); \/\/ $str\u5168\u4f53\u3092\u53d6\u5f97\uff08\"example\"\uff09\n<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u57fa\u790e\u77e5\u8b58\u3092\u62bc\u3055\u3048\u308b\u3053\u3068\u3067\u3001<code>substr<\/code>\u95a2\u6570\u3092\u69d8\u3005\u306a\u72b6\u6cc1\u3067\u9069\u5207\u306b\u6d3b\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3055\u3089\u306b\u5b9f\u8df5\u7684\u306a\u6d3b\u7528\u6cd5\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-22\">\u5b9f\u8df5\u7684\u306aPHP substr\u6d3b\u7528\u6cd5<\/h2>\n\n\n\n<p>\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\u3092\u7406\u89e3\u3057\u305f\u3068\u3053\u308d\u3067\u3001\u5b9f\u969b\u306e\u958b\u767a\u30b7\u30fc\u30f3\u3067\u5f79\u7acb\u3064<code>substr<\/code>\u306e\u5b9f\u8df5\u7684\u306a\u6d3b\u7528\u6cd5\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002\u3053\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u5177\u4f53\u7684\u306a\u30b3\u30fc\u30c9\u4f8b\u3092\u901a\u3058\u3066\u3001\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u69d8\u3005\u306a\u30c6\u30af\u30cb\u30c3\u30af\u3092\u7fd2\u5f97\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-23\">\u6587\u5b57\u5217\u306e\u5148\u982d\u304b\u3089\u6307\u5b9a\u6587\u5b57\u6570\u3092\u53d6\u5f97\u3059\u308b\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u5148\u982d\u304b\u3089\u306e\u6587\u5b57\u5217\u53d6\u5f97\u306f\u3001\u6700\u3082\u57fa\u672c\u7684\u3067\u983b\u7e41\u306b\u4f7f\u308f\u308c\u308b\u30d1\u30bf\u30fc\u30f3\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-24\">1. \u56fa\u5b9a\u9577\u306e\u6587\u5b57\u5217\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5148\u982d\u304b\u308910\u6587\u5b57\u3092\u53d6\u5f97\u3057\u3066\u30bf\u30a4\u30c8\u30eb\u3092\u77ed\u7e2e\u8868\u793a\n$longTitle = \"PHP\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306e\u5b8c\u5168\u30ac\u30a4\u30c9\uff1a\u521d\u5fc3\u8005\u304b\u3089\u4e0a\u7d1a\u8005\u307e\u3067\";\n$shortTitle = substr($longTitle, 0, 10) . '...';\necho $shortTitle; \/\/ \u51fa\u529b: \"PHP\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0...\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-25\">2. \u30e6\u30fc\u30b6\u30fc\u5165\u529b\u306e\u5b89\u5168\u306a\u51e6\u7406<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30e6\u30fc\u30b6\u30fc\u540d\u306e\u5148\u982d\u90e8\u5206\u306e\u307f\u3092\u8868\u793a\u3057\u3066\u30d7\u30e9\u30a4\u30d0\u30b7\u30fc\u4fdd\u8b77\n$username = \"tanaka_taro123\";\n$maskedName = substr($username, 0, 3) . str_repeat('*', strlen($username) - 3);\necho $maskedName; \/\/ \u51fa\u529b: \"tan**********\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-26\">3. \u6761\u4ef6\u5224\u5b9a\u306e\u305f\u3081\u306e\u30d7\u30ec\u30d5\u30a3\u30c3\u30af\u30b9\u30c1\u30a7\u30c3\u30af<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ URL\u306e\u30d7\u30ed\u30c8\u30b3\u30eb\u3092\u78ba\u8a8d\u3059\u308b\n$url = \"https:\/\/example.com\";\nif (substr($url, 0, 8) === 'https:\/\/') {\n    echo \"\u30bb\u30ad\u30e5\u30a2\u306a\u63a5\u7d9a\u3067\u3059\";\n} elseif (substr($url, 0, 7) === 'http:\/\/') {\n    echo \"\u975e\u30bb\u30ad\u30e5\u30a2\u306a\u63a5\u7d9a\u3067\u3059\";\n}\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-27\">\u6587\u5b57\u5217\u306e\u672b\u5c3e\u304b\u3089\u6307\u5b9a\u6587\u5b57\u6570\u3092\u53d6\u5f97\u3059\u308b\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>\u672b\u5c3e\u304b\u3089\u306e\u6587\u5b57\u5217\u53d6\u5f97\u306f\u3001\u30d5\u30a1\u30a4\u30eb\u62e1\u5f35\u5b50\u306e\u5224\u5b9a\u3084\u63a5\u5c3e\u8f9e\u306e\u51e6\u7406\u306b\u7279\u306b\u4fbf\u5229\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-28\">1. \u8ca0\u306e\u30aa\u30d5\u30bb\u30c3\u30c8\u3092\u4f7f\u7528\u3057\u305f\u672b\u5c3e\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30d5\u30a1\u30a4\u30eb\u540d\u304b\u3089\u62e1\u5f35\u5b50\u3092\u62bd\u51fa\n$filename = \"document.report.pdf\";\n$extension = substr($filename, -3);\necho $extension; \/\/ \u51fa\u529b: \"pdf\"\n\n\/\/ \u3088\u308a\u5805\u7262\u306a\u65b9\u6cd5\uff08\u30c9\u30c3\u30c8\u306e\u4f4d\u7f6e\u304b\u3089\u62bd\u51fa\uff09\n$betterExtension = substr($filename, strrpos($filename, '.') + 1);\necho $betterExtension; \/\/ \u51fa\u529b: \"pdf\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-29\">2. \u672b\u5c3e\u306e\u60c5\u5831\u3092\u4f7f\u3063\u305f\u6761\u4ef6\u5224\u5b9a<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u753b\u50cf\u30d5\u30a1\u30a4\u30eb\u304b\u3069\u3046\u304b\u3092\u62e1\u5f35\u5b50\u3067\u5224\u5b9a\n$isImage = in_array(substr($filename, -4), ['.jpg', '.png', 'jpeg', '.gif']);\n\n\/\/ \u3088\u308a\u5805\u7262\u306a\u65b9\u6cd5\n$ext = strtolower(substr($filename, strrpos($filename, '.') + 1));\n$isImageBetter = in_array($ext, ['jpg', 'png', 'jpeg', 'gif']);\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-30\">\u6587\u5b57\u5217\u306e\u4e2d\u9593\u90e8\u5206\u3092\u62bd\u51fa\u3059\u308b\u5b9f\u7528\u4f8b<\/h3>\n\n\n\n<p>\u4e2d\u9593\u90e8\u5206\u306e\u62bd\u51fa\u306f\u3001\u56fa\u5b9a\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u306e\u30c7\u30fc\u30bf\u51e6\u7406\u3084\u7279\u5b9a\u30d1\u30bf\u30fc\u30f3\u9593\u306e\u30b3\u30f3\u30c6\u30f3\u30c4\u53d6\u5f97\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-31\">1. \u56fa\u5b9a\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u30c7\u30fc\u30bf\u304b\u3089\u306e\u62bd\u51fa<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ YYYY-MM-DD\u5f62\u5f0f\u306e\u65e5\u4ed8\u304b\u3089\u6708\u3060\u3051\u3092\u53d6\u5f97\n$date = \"2023-05-15\";\n$month = substr($date, 5, 2);\necho $month; \/\/ \u51fa\u529b: \"05\"\n\n\/\/ \u6642\u9593\u5f62\u5f0fHH:MM:SS\u304b\u3089\u5206\u3060\u3051\u3092\u53d6\u5f97\n$time = \"14:30:25\";\n$minutes = substr($time, 3, 2);\necho $minutes; \/\/ \u51fa\u529b: \"30\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-32\">2. \u52d5\u7684\u306a\u4f4d\u7f6e\u304b\u3089\u306e\u62bd\u51fa<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u7279\u5b9a\u306e\u30de\u30fc\u30ab\u30fc\u9593\u306e\u30c6\u30ad\u30b9\u30c8\u3092\u62bd\u51fa\n$text = \"Start[\u5b9f\u969b\u306e\u30b3\u30f3\u30c6\u30f3\u30c4]End\";\n$startPos = strpos($text, '[') + 1;\n$endPos = strpos($text, ']');\n$content = substr($text, $startPos, $endPos - $startPos);\necho $content; \/\/ \u51fa\u529b: \"\u5b9f\u969b\u306e\u30b3\u30f3\u30c6\u30f3\u30c4\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-33\">3. \u5b9f\u7528\u7684\u306a\u30c7\u30fc\u30bf\u52a0\u5de5\u4f8b<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30af\u30ec\u30b8\u30c3\u30c8\u30ab\u30fc\u30c9\u756a\u53f7\u3092\u90e8\u5206\u7684\u306b\u30de\u30b9\u30af\n$cardNumber = \"4111222233334444\";\n$maskedCard = substr($cardNumber, 0, 4) . ' ' . \n              substr($cardNumber, 4, 4) . ' ' . \n              substr($cardNumber, 8, 4) . ' ' . \n              substr($cardNumber, 12);\necho $maskedCard; \/\/ \u51fa\u529b: \"4111 2222 3333 4444\"\n\n\/\/ \u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u306e\u305f\u3081\u4e2d\u9593\u90e8\u5206\u3092\u30de\u30b9\u30af\n$secureCard = substr($cardNumber, 0, 4) . ' **** **** ' . \n              substr($cardNumber, -4);\necho $secureCard; \/\/ \u51fa\u529b: \"4111 **** **** 4444\"\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-34\">\u8ca0\u306e\u6570\u3092\u4f7f\u3063\u305f\u9006\u5f15\u304d\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u6307\u5b9a\u306e\u6d3b\u7528\u6cd5<\/h3>\n\n\n\n<p>\u8ca0\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3092\u4f7f\u7528\u3059\u308b\u3068\u3001\u6587\u5b57\u5217\u306e\u672b\u5c3e\u3092\u57fa\u6e96\u306b\u3057\u305f\u67d4\u8edf\u306a\u64cd\u4f5c\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-35\">1. \u672b\u5c3e\u306e\u7279\u5b9a\u90e8\u5206\u3092\u9664\u5916\u3057\u305f\u62bd\u51fa<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u6587\u5b57\u5217\u304b\u3089\u6700\u5f8c\u306e3\u6587\u5b57\u3092\u9664\u3044\u305f\u90e8\u5206\u3092\u53d6\u5f97\n$string = \"report.docx\";\n$withoutExt = substr($string, 0, -5); \/\/ .docx\u3092\u9664\u53bb\necho $withoutExt; \/\/ \u51fa\u529b: \"report\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-36\">2. \u672b\u5c3e\u304b\u3089\u7279\u5b9a\u7bc4\u56f2\u3092\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u672b\u5c3e\u304b\u30895\u6587\u5b57\u76ee\u304b\u3089\u3001\u672b\u5c3e\u304b\u30892\u6587\u5b57\u76ee\u307e\u3067\u3092\u53d6\u5f97\n$code = \"ABC-12345-XYZ\";\n$middle = substr($code, -8, 5);\necho $middle; \/\/ \u51fa\u529b: \"12345\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-37\">3. \u4e21\u7aef\u304b\u3089\u9664\u5916\u3057\u305f\u4e2d\u9593\u90e8\u5206\u306e\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ JSON\u6587\u5b57\u5217\u304b\u3089\u62ec\u5f27\u3092\u9664\u3044\u305f\u4e2d\u8eab\u3060\u3051\u3092\u53d6\u5f97\n$json = '{\"name\":\"value\",\"code\":123}';\n$content = substr($json, 1, -1);\necho $content; \/\/ \u51fa\u529b: \"name\":\"value\",\"code\":123\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-38\">4. \u8907\u96d1\u306a\u30c7\u30fc\u30bf\u51e6\u7406\u306e\u4f8b<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ HTML\u30bf\u30b0\u3092\u9664\u53bb\u3057\u3066\u30d7\u30ec\u30fc\u30f3\u30c6\u30ad\u30b9\u30c8\u3092\u53d6\u5f97\u3059\u308b\u7c21\u6613\u5b9f\u88c5\nfunction stripSimpleTag($html, $tag) {\n    $openTag = '&lt;' . $tag . '&gt;';\n    $closeTag = '&lt;\/' . $tag . '&gt;';\n    $startPos = strpos($html, $openTag);\n    $endPos = strpos($html, $closeTag);\n    \n    if ($startPos !== false &amp;&amp; $endPos !== false) {\n        \/\/ \u30bf\u30b0\u306e\u524d\u306e\u90e8\u5206\n        $before = substr($html, 0, $startPos);\n        \/\/ \u30bf\u30b0\u306e\u5f8c\u306e\u90e8\u5206\n        $after = substr($html, $endPos + strlen($closeTag));\n        \/\/ \u30bf\u30b0\u306e\u4e2d\u8eab\n        $content = substr($html, $startPos + strlen($openTag), $endPos - $startPos - strlen($openTag));\n        \n        return $before . $content . $after;\n    }\n    \n    return $html;\n}\n\n$html = '&lt;p&gt;\u3053\u308c\u306f&lt;strong&gt;\u91cd\u8981\u306a&lt;\/strong&gt;\u30c6\u30ad\u30b9\u30c8\u3067\u3059&lt;\/p&gt;';\n$plain = stripSimpleTag($html, 'strong');\necho $plain; \/\/ \u51fa\u529b: &lt;p&gt;\u3053\u308c\u306f\u91cd\u8981\u306a\u30c6\u30ad\u30b9\u30c8\u3067\u3059&lt;\/p&gt;\n<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5b9f\u8df5\u7684\u306a\u4f8b\u3092\u901a\u3058\u3066\u3001<code>substr<\/code>\u95a2\u6570\u304c\u3044\u304b\u306b\u591a\u69d8\u306a\u5834\u9762\u3067\u6d3b\u7528\u3067\u304d\u308b\u304b\u304c\u308f\u304b\u308a\u307e\u3059\u3002\u5358\u7d14\u306a\u304c\u3089\u3082\u5f37\u529b\u306a\u3053\u306e\u95a2\u6570\u3092\u30de\u30b9\u30bf\u30fc\u3059\u308b\u3053\u3068\u3067\u3001PHP\u3067\u306e\u6587\u5b57\u5217\u51e6\u7406\u304c\u3088\u308a\u52b9\u7387\u7684\u306b\u306a\u308b\u3067\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<p>\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3055\u3089\u306b\u4e00\u6b69\u9032\u3093\u3067\u3001<code>substr<\/code>\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af\u3092\u63a2\u3063\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-39\">PHP substr\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af<\/h2>\n\n\n\n<p>\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\u3068\u5b9f\u8df5\u4f8b\u3092\u7406\u89e3\u3057\u305f\u3068\u3053\u308d\u3067\u3001\u3055\u3089\u306b\u4e00\u6b69\u9032\u3093\u3067<code>substr<\/code>\u95a2\u6570\u306e\u5fdc\u7528\u30c6\u30af\u30cb\u30c3\u30af\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002\u4ed6\u306e\u5236\u5fa1\u69cb\u9020\u3084\u95a2\u6570\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u67d4\u8edf\u3067\u9ad8\u5ea6\u306a\u6587\u5b57\u5217\u64cd\u4f5c\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-40\">\u6761\u4ef6\u5206\u5c90\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\u306b\u3088\u308b\u67d4\u8edf\u306a\u6587\u5b57\u5217\u51e6\u7406<\/h3>\n\n\n\n<p><code>substr<\/code>\u3068\u6761\u4ef6\u5206\u5c90\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u72b6\u6cc1\u306b\u5fdc\u3058\u305f\u67d4\u8edf\u306a\u6587\u5b57\u5217\u64cd\u4f5c\u304c\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-41\">\u9577\u3044URL\u306e\u52d5\u7684\u306a\u77ed\u7e2e\u8868\u793a<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u9577\u3044URL\u3092\u753b\u9762\u30b5\u30a4\u30ba\u306b\u5408\u308f\u305b\u3066\u77ed\u7e2e\u8868\u793a\u3059\u308b\nfunction shortenUrl($url, $maxLength = 30) {\n    if (strlen($url) &lt;= $maxLength) {\n        return $url; \/\/ \u77ed\u3044\u5834\u5408\u306f\u305d\u306e\u307e\u307e\u8868\u793a\n    }\n    \n    \/\/ \u9577\u3044\u5834\u5408\u306f\u4e2d\u9593\u3092\u300c...\u300d\u3067\u7f6e\u63db\n    return substr($url, 0, $maxLength \/ 2 - 2) . '...' . \n           substr($url, -($maxLength \/ 2) + 2);\n}\n\n$longUrl = \"https:\/\/example.com\/very\/long\/path\/to\/some\/resource.html?param=value\";\necho shortenUrl($longUrl); \/\/ \u51fa\u529b: \"https:\/\/example.com\/v...ource.html?param=value\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-42\">\u6a29\u9650\u30ec\u30d9\u30eb\u306b\u5fdc\u3058\u305f\u60c5\u5831\u8868\u793a<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30e6\u30fc\u30b6\u30fc\u6a29\u9650\u30ec\u30d9\u30eb\u306b\u5fdc\u3058\u3066\u8868\u793a\u3059\u308b\u60c5\u5831\u3092\u8abf\u6574\nfunction getUserInfo($userData, $userLevel) {\n    \/\/ \u57fa\u672c\u60c5\u5831\uff08\u5168\u30e6\u30fc\u30b6\u30fc\u5411\u3051\uff09\n    $visibleInfo = substr($userData, 0, 50);\n    \n    \/\/ \u30ec\u30d9\u30eb2\u4ee5\u4e0a\u306e\u30e6\u30fc\u30b6\u30fc\u306b\u306f\u8ffd\u52a0\u60c5\u5831\u3092\u8868\u793a\n    if ($userLevel &gt;= 2) {\n        $visibleInfo .= substr($userData, 50, 30);\n    }\n    \n    \/\/ \u7ba1\u7406\u8005\uff08\u30ec\u30d9\u30eb4\uff09\u306b\u306f\u5168\u60c5\u5831\u3092\u8868\u793a\n    if ($userLevel &gt;= 4) {\n        $visibleInfo .= substr($userData, 80);\n    }\n    \n    return $visibleInfo;\n}\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-43\">\u30eb\u30fc\u30d7\u51e6\u7406\u3068\u306e\u9023\u643a\u3067\u5b9f\u73fe\u3059\u308b\u9ad8\u5ea6\u306a\u6587\u5b57\u5217\u64cd\u4f5c<\/h3>\n\n\n\n<p>\u30eb\u30fc\u30d7\u3068<code>substr<\/code>\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u8907\u96d1\u306a\u6587\u5b57\u5217\u51e6\u7406\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002\u7279\u306b\u6587\u5b57\u5358\u4f4d\u306e\u64cd\u4f5c\u3084\u5927\u304d\u306a\u30c6\u30ad\u30b9\u30c8\u306e\u5206\u5272\u51e6\u7406\u306b\u5a01\u529b\u3092\u767a\u63ee\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-44\">\u7c21\u6613\u7684\u306a\u6587\u5b57\u7f6e\u63db\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u6587\u5b57\u5217\u5185\u306e\u7279\u5b9a\u4f4d\u7f6e\u306b\u3042\u308b\u6587\u5b57\u3092\u7f6e\u63db\u3059\u308b\u30ab\u30b9\u30bf\u30e0\u95a2\u6570\nfunction replaceAt($string, $replacements) {\n    \/\/ \u7f6e\u63db\u3059\u308b\u6587\u5b57\u304b\u3089\u4f5c\u6210\u3059\u308b\u65b0\u3057\u3044\u6587\u5b57\u5217\n    $result = '';\n    \n    \/\/ 1\u6587\u5b57\u305a\u3064\u51e6\u7406\n    for ($i = 0; $i &lt; strlen($string); $i++) {\n        $char = substr($string, $i, 1);\n        \/\/ \u7f6e\u63db\u5bfe\u8c61\u306e\u4f4d\u7f6e\u304b\u3069\u3046\u304b\u3092\u30c1\u30a7\u30c3\u30af\n        if (isset($replacements[$i])) {\n            $result .= $replacements[$i];\n        } else {\n            $result .= $char;\n        }\n    }\n    \n    return $result;\n}\n\n$text = \"Hello, World!\";\n$changes = [1 =&gt; 'a', 4 =&gt; 'y', 7 =&gt; 'Z'];\necho replaceAt($text, $changes); \/\/ \u51fa\u529b: \"Hallo, Zorld!\"\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-45\">\u30b9\u30e9\u30a4\u30c7\u30a3\u30f3\u30b0\u30a6\u30a3\u30f3\u30c9\u30a6\u6cd5\u306b\u3088\u308b\u90e8\u5206\u6587\u5b57\u5217\u691c\u7d22<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30b9\u30e9\u30a4\u30c7\u30a3\u30f3\u30b0\u30a6\u30a3\u30f3\u30c9\u30a6\u6cd5\u3067\u7279\u5b9a\u306e\u30d1\u30bf\u30fc\u30f3\u306e\u51fa\u73fe\u4f4d\u7f6e\u3092\u5168\u3066\u898b\u3064\u3051\u308b\nfunction findAllOccurrences($text, $pattern) {\n    $positions = [];\n    $patternLength = strlen($pattern);\n    \n    \/\/ \u30c6\u30ad\u30b9\u30c8\u5185\u3092\u9806\u306b\u79fb\u52d5\n    for ($i = 0; $i &lt;= strlen($text) - $patternLength; $i++) {\n        $window = substr($text, $i, $patternLength);\n        \n        if ($window === $pattern) {\n            $positions[] = $i;\n        }\n    }\n    \n    return $positions;\n}\n\n$text = \"abracadabra\";\n$positions = findAllOccurrences($text, \"abra\");\nprint_r($positions); \/\/ \u51fa\u529b: Array ( [0] =&gt; 0 [1] =&gt; 7 )\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-46\">\u6b63\u898f\u8868\u73fe\u3068\u306e\u4f7f\u3044\u5206\u3051\u3067\u52b9\u7387\u7684\u306a\u30b3\u30fc\u30c9\u3092\u5b9f\u73fe\u3059\u308b\u65b9\u6cd5<\/h3>\n\n\n\n<p><code>substr<\/code>\u3068\u6b63\u898f\u8868\u73fe\u306f\u305d\u308c\u305e\u308c\u5f97\u610f\u5206\u91ce\u304c\u7570\u306a\u308a\u307e\u3059\u3002\u9069\u5207\u306b\u4f7f\u3044\u5206\u3051\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u52b9\u7387\u7684\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-47\">substr vs \u6b63\u898f\u8868\u73fe\u306e\u6bd4\u8f03<\/h4>\n\n\n<div id=\"id-a2abd9d6-c372-40bc-822e-2c4790d300c7\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7279\u6027<\/th><th>substr<\/th><th>\u6b63\u898f\u8868\u73fe<\/th><\/tr><\/thead><tbody><tr><td>\u901f\u5ea6<\/td><td>\u4e00\u822c\u7684\u306b\u9ad8\u901f<\/td><td>\u30d1\u30bf\u30fc\u30f3\u8907\u96d1\u6027\u306b\u4f9d\u5b58<\/td><\/tr><tr><td>\u8907\u96d1\u3055<\/td><td>\u30b7\u30f3\u30d7\u30eb<\/td><td>\u5b66\u7fd2\u66f2\u7dda\u304c\u6025<\/td><\/tr><tr><td>\u67d4\u8edf\u6027<\/td><td>\u56fa\u5b9a\u4f4d\u7f6e\u306e\u307f<\/td><td>\u8907\u96d1\u306a\u30d1\u30bf\u30fc\u30f3\u306b\u5bfe\u5fdc<\/td><\/tr><tr><td>\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf<\/td><td>\u5c11\u306a\u3044<\/td><td>\u6bd4\u8f03\u7684\u591a\u3044<\/td><\/tr><tr><td>\u30b3\u30fc\u30c9\u53ef\u8aad\u6027<\/td><td>\u9ad8\u3044<\/td><td>\u30d1\u30bf\u30fc\u30f3\u304c\u8907\u96d1\u306b\u306a\u308b\u3068\u4f4e\u4e0b<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h4 class=\"wp-block-heading\" id=\"i-48\">substr\u3092\u4f7f\u3046\u3079\u304d\u5834\u9762<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f4d\u7f6e\u304c\u660e\u78ba\u306a\u90e8\u5206\u6587\u5b57\u5217\u306e\u62bd\u51fa<\/li>\n\n\n\n<li>\u30b7\u30f3\u30d7\u30eb\u306a\u6587\u5b57\u5217\u5206\u5272<\/li>\n\n\n\n<li>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u91cd\u8981\u306a\u7e70\u308a\u8fd4\u3057\u51e6\u7406<\/li>\n\n\n\n<li>\u56fa\u5b9a\u9577\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u306e\u30c7\u30fc\u30bf\u51e6\u7406<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30e6\u30fc\u30b6\u30fc\u30b3\u30fc\u30c9\u306e\u691c\u8a3c\uff08\u5148\u982d2\u6587\u5b57\u304c\u90e8\u9580\u30b3\u30fc\u30c9\u3001\u6b21\u306e4\u6587\u5b57\u304c\u793e\u54e1\u756a\u53f7\uff09\n$userCode = \"HR1234XYZ\";\n$department = substr($userCode, 0, 2);\n$employeeNumber = substr($userCode, 2, 4);\n\n\/\/ \u9ad8\u901f\u306b\u51e6\u7406\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u5834\u5408\u3001substr\u306e\u65b9\u304c\u52b9\u7387\u7684\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-49\">\u6b63\u898f\u8868\u73fe\u3092\u4f7f\u3046\u3079\u304d\u5834\u9762<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8907\u96d1\u306a\u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0<\/li>\n\n\n\n<li>\u67d4\u8edf\u306a\u30c6\u30ad\u30b9\u30c8\u62bd\u51fa<\/li>\n\n\n\n<li>\u4e00\u5ea6\u306b\u8907\u6570\u306e\u30de\u30c3\u30c1\u30f3\u30b0\u3092\u53d6\u5f97\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b<\/li>\n\n\n\n<li>\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u30eb\u30fc\u30eb\u304c\u8907\u96d1\u306a\u5834\u5408<\/li>\n<\/ul>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u304b\u3089\u30e6\u30fc\u30b6\u30fc\u540d\u3068\u30c9\u30e1\u30a4\u30f3\u3092\u62bd\u51fa\u3059\u308b\n$email = \"user.name@example.com\";\nif (preg_match('\/^(.+)@(.+)$\/', $email, $matches)) {\n    $username = $matches[1]; \/\/ user.name\n    $domain = $matches[2];   \/\/ example.com\n}\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-50\">\u30cf\u30a4\u30d6\u30ea\u30c3\u30c9\u30a2\u30d7\u30ed\u30fc\u30c1<\/h4>\n\n\n\n<p>\u5b9f\u969b\u306e\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u306f\u3001\u4e21\u65b9\u306e\u6280\u8853\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3068\u52b9\u679c\u7684\u3067\u3059\u3002<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ HTTP\u30ec\u30b9\u30dd\u30f3\u30b9\u304b\u3089JSON\u30dc\u30c7\u30a3\u90e8\u5206\u3092\u62bd\u51fa\u3057\u3001\u7279\u5b9a\u306e\u5024\u3092\u53d6\u308a\u51fa\u3059\nfunction extractValueFromResponse($response) {\n    \/\/ \u30d8\u30c3\u30c0\u30fc\u3068\u30dc\u30c7\u30a3\u306e\u533a\u5207\u308a\u3092\u898b\u3064\u3051\u308b\n    $bodyStart = strpos($response, \"\\r\\n\\r\\n\") + 4;\n    \n    \/\/ \u30dc\u30c7\u30a3\u90e8\u5206\u3092substr\u3067\u62bd\u51fa\uff08\u9ad8\u901f\uff09\n    $body = substr($response, $bodyStart);\n    \n    \/\/ \u7279\u5b9a\u306e\u5024\u3092\u6b63\u898f\u8868\u73fe\u3067\u62bd\u51fa\uff08\u67d4\u8edf\uff09\n    if (preg_match('\/\"result\":\"([^\"]+)\"\/', $body, $matches)) {\n        return $matches[1];\n    }\n    \n    return null;\n}\n<\/pre>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306bsubstr\u95a2\u6570\u306f\u4ed6\u306e\u5236\u5fa1\u69cb\u9020\u3084\u95a2\u6570\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u975e\u5e38\u306b\u5f37\u529b\u306a\u6587\u5b57\u5217\u51e6\u7406\u30c4\u30fc\u30eb\u3068\u306a\u308a\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001substr\u4f7f\u7528\u6642\u306e\u30a8\u30e9\u30fc\u56de\u907f\u3068\u5bfe\u7b56\u306b\u3064\u3044\u3066\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-51\">PHP substr\u306e\u30a8\u30e9\u30fc\u56de\u907f\u3068\u5bfe\u7b56<\/h2>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306f\u6bd4\u8f03\u7684\u30b7\u30f3\u30d7\u30eb\u306a\u95a2\u6570\u3067\u3059\u304c\u3001\u9069\u5207\u306b\u4f7f\u7528\u3057\u306a\u3044\u3068\u30a8\u30e9\u30fc\u3084\u4e88\u671f\u3057\u306a\u3044\u7d50\u679c\u3092\u5f15\u304d\u8d77\u3053\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u4e00\u822c\u7684\u306a\u554f\u984c\u3068\u305d\u306e\u5bfe\u51e6\u6cd5\u3092\u5b66\u3073\u3001\u3088\u308a\u5805\u7262\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-52\">\u3088\u304f\u3042\u308bsubstr\u95a2\u9023\u30a8\u30e9\u30fc\u3068\u30c7\u30d0\u30c3\u30b0\u65b9\u6cd5<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-53\">\u4e3b\u306a\u8b66\u544a\u3068\u30a8\u30e9\u30fc<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>NULL\u5024\u3092\u6e21\u3057\u305f\u5834\u5408\u306e\u8b66\u544a\uff08PHP 8\u4ee5\u964d\uff09<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ PHP 8\u3067\u306f\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3067\u8b66\u544a\u304c\u767a\u751f\n$value = null;\n$result = substr($value, 0, 5);\n\/\/ Warning: substr(): Passing null to parameter #1 ($string) of type string is deprecated\n<\/pre>\n\n\n\n<p>PHP 7\u307e\u3067\u306f\u6697\u9ed9\u7684\u306bNULL\u3092\u7a7a\u6587\u5b57\u5217\u3068\u3057\u3066\u6271\u3063\u3066\u3044\u307e\u3057\u305f\u304c\u3001PHP 8\u304b\u3089\u306f\u975e\u63a8\u5968\u8b66\u544a\u304c\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u4e88\u671f\u3057\u306a\u3044\u7d50\u679c\uff08\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\uff09<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$japanese = \"\u3053\u3093\u306b\u3061\u306f\u4e16\u754c\";\necho substr($japanese, 0, 3); \/\/ \u51fa\u529b: \u6587\u5b57\u5316\u3051\u307e\u305f\u306f\u4e0d\u5b8c\u5168\u306a\u6587\u5b57\u5217\n<\/pre>\n\n\n\n<p>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6271\u3046\u5834\u5408\u3001\u901a\u5e38\u306e<code>substr<\/code>\u3067\u306f\u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u5207\u308a\u53d6\u308b\u305f\u3081\u3001\u6587\u5b57\u304c\u9014\u4e2d\u3067\u5207\u308c\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-54\">\u52b9\u679c\u7684\u306a\u30c7\u30d0\u30c3\u30b0\u65b9\u6cd5<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5165\u51fa\u529b\u306e\u53ef\u8996\u5316<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u95a2\u6570\u306e\u5165\u51fa\u529b\u3092\u78ba\u8a8d\n$string = \"example\";\n$offset = 2;\n$length = 3;\n\nvar_dump([\n    'input_string' =&gt; $string,\n    'string_length' =&gt; strlen($string),\n    'offset' =&gt; $offset,\n    'length' =&gt; $length,\n    'result' =&gt; substr($string, $offset, $length)\n]);\n<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30a8\u30e9\u30fc\u306e\u8868\u793a\u8a2d\u5b9a<\/strong><\/li>\n<\/ol>\n\n\n\n<p>\u958b\u767a\u74b0\u5883\u3067\u306f\u3001\u3059\u3079\u3066\u306e\u30a8\u30e9\u30fc\u3092\u8868\u793a\u3059\u308b\u3088\u3046\u306b\u8a2d\u5b9a\u3059\u308b\u3068\u3001\u554f\u984c\u3092\u65e9\u671f\u306b\u767a\u898b\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u958b\u767a\u74b0\u5883\u3067\u306e\u307f\u4f7f\u7528\nerror_reporting(E_ALL);\nini_set('display_errors', 1);\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-55\">\u7a7a\u6587\u5b57\u5217\u3084\u7121\u52b9\u306a\u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u3078\u306e\u5bfe\u5fdc\u7b56<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-56\">\u5b89\u5168\u306asubstr\u4f7f\u7528\u30d1\u30bf\u30fc\u30f3<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function safeSubstr($string, $offset, $length = null) {\n    \/\/ NULL\u5024\u3068\u7a7a\u6587\u5b57\u5217\u306e\u30c1\u30a7\u30c3\u30af\n    if ($string === null || $string === '') {\n        return '';\n    }\n    \n    \/\/ \u6587\u5b57\u5217\u578b\u3078\u306e\u5f37\u5236\u5909\u63db\n    $string = (string)$string;\n    \n    \/\/ \u30a4\u30f3\u30c7\u30c3\u30af\u30b9\u7bc4\u56f2\u306e\u691c\u8a3c\n    if (abs($offset) &gt; strlen($string)) {\n        return '';\n    }\n    \n    return substr($string, $offset, $length);\n}\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-57\">\u30a8\u30c3\u30b8\u30b1\u30fc\u30b9\u5bfe\u5fdc\u306e\u305f\u3081\u306e\u30d8\u30eb\u30d1\u30fc\u95a2\u6570<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function extractWithDefault($string, $offset, $length = null, $default = '') {\n    \/\/ PHP 8\u306eNull\u5408\u4f53\u6f14\u7b97\u5b50\u3092\u4f7f\u7528\u3057\u3066 NULL \u5bfe\u5fdc\n    $result = substr($string ?? '', $offset, $length);\n    \n    \/\/ \u7d50\u679c\u304c\u7a7a\u306e\u5834\u5408\u306b\u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u3092\u8fd4\u3059\n    return $result === '' ? $default : $result;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$email = null;\necho extractWithDefault($email, 0, 5, 'N\/A'); \/\/ \u51fa\u529b: N\/A\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-58\">\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6700\u9069\u5316\u306e\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h3>\n\n\n\n<p><code>substr<\/code>\u306f\u975e\u5e38\u306b\u9ad8\u901f\u306a\u95a2\u6570\u3067\u3059\u304c\u3001\u3055\u3089\u306b\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u5411\u4e0a\u3055\u305b\u308b\u305f\u3081\u306e\u30c6\u30af\u30cb\u30c3\u30af\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-59\">\u6700\u9069\u5316\u306e\u30dd\u30a4\u30f3\u30c8<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u7e70\u308a\u8fd4\u3057\u8a08\u7b97\u3092\u907f\u3051\u308b<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u60aa\u3044\u4f8b\nfor ($i = 0; $i &lt; count($items); $i++) {\n    $prefix = substr($longString, 0, 10);\n    \/\/ \u6bce\u56de\u540c\u3058\u8a08\u7b97\u3092\u5b9f\u884c\u3057\u3066\u3044\u308b\n}\n\n\/\/ \u826f\u3044\u4f8b\n$prefix = substr($longString, 0, 10);\nfor ($i = 0; $i &lt; count($items); $i++) {\n    \/\/ $prefix\u3092\u518d\u5229\u7528\n}\n<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u76ee\u7684\u306b\u5408\u3063\u305f\u95a2\u6570\u3092\u9078\u3076<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u6587\u5b57\u5217\u304c\u7279\u5b9a\u306e\u30d7\u30ec\u30d5\u30a3\u30c3\u30af\u30b9\u3067\u59cb\u307e\u308b\u304b\u30c1\u30a7\u30c3\u30af\n\/\/ \u975e\u52b9\u7387\u7684\nif (substr($url, 0, 8) === 'https:\/\/') {\n    \/\/ \u51e6\u7406\n}\n\n\/\/ \u52b9\u7387\u7684\uff08PHP 8\u4ee5\u964d\uff09\nif (str_starts_with($url, 'https:\/\/')) {\n    \/\/ \u51e6\u7406\n}\n\n\/\/ \u52b9\u7387\u7684\uff08PHP 7\u4ee5\u524d\uff09\nif (strpos($url, 'https:\/\/') === 0) {\n    \/\/ \u51e6\u7406\n}\n<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>\u4e0d\u8981\u306a\u95a2\u6570\u547c\u3073\u51fa\u3057\u3092\u6e1b\u3089\u3059<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u60aa\u3044\u4f8b\nif (substr($email, strpos($email, '@')) !== false) {\n    \/\/ @\u4ee5\u964d\u3092\u53d6\u5f97\n    $domain = substr($email, strpos($email, '@') + 1);\n}\n\n\/\/ \u826f\u3044\u4f8b\n$atPos = strpos($email, '@');\nif ($atPos !== false) {\n    $domain = substr($email, $atPos + 1);\n}\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-60\">\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u6bd4\u8f03<\/h4>\n\n\n\n<p>\u5b9f\u969b\u306e\u30d9\u30f3\u30c1\u30de\u30fc\u30af\u3067\u306f\u3001<code>substr<\/code>\u306f\u6b63\u898f\u8868\u73fe\u306b\u6bd4\u3079\u3066\u7d047\u500d\u9ad8\u901f\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u5358\u7d14\u306a\u62bd\u51fa\u30bf\u30b9\u30af\uff08\u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u304b\u3089\u30e6\u30fc\u30b6\u30fc\u540d\u3092\u62bd\u51fa\uff09\u306e\u6bd4\u8f03\n\/\/ substr: 0.012\u79d2 vs \u6b63\u898f\u8868\u73fe: 0.089\u79d2 (10,000\u56de\u5b9f\u884c)\n<\/pre>\n\n\n\n<p>\u307e\u305f\u3001ASCII\u306e\u307f\u306e\u6587\u5b57\u5217\u3092\u51e6\u7406\u3059\u308b\u5834\u5408\u3001<code>substr<\/code>\u306f<code>mb_substr<\/code>\u3088\u308a\u7d044\u500d\u9ad8\u901f\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ ASCII\u6587\u5b57\u5217\u306e\u51e6\u7406\uff0810,000\u56de\u5b9f\u884c\uff09\n\/\/ substr: 0.008\u79d2 vs mb_substr: 0.032\u79d2\n<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5bfe\u7b56\u3068\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u3092\u9069\u7528\u3059\u308b\u3053\u3068\u3067\u3001<code>substr<\/code>\u95a2\u6570\u3092\u3088\u308a\u5b89\u5168\u304b\u3064\u52b9\u7387\u7684\u306b\u6d3b\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u305f\u3081\u306e<code>mb_substr<\/code>\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-61\">\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u5bfe\u5fdc\u306e\u305f\u3081\u306emb_substr<\/h2>\n\n\n\n<p>\u65e5\u672c\u8a9e\u3084\u4e2d\u56fd\u8a9e\u306a\u3069\u306e\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6271\u3046Web\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u306f\u3001\u6a19\u6e96\u306e<code>substr<\/code>\u95a2\u6570\u3067\u306f\u6b63\u3057\u304f\u6587\u5b57\u5217\u3092\u51e6\u7406\u3067\u304d\u306a\u3044\u30b1\u30fc\u30b9\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u9069\u5207\u306b\u6271\u3046\u305f\u3081\u306e<code>mb_substr<\/code>\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-62\">PHP substr\u3068mb_substr\u306e\u9055\u3044\u3068\u4f7f\u3044\u5206\u3051<\/h3>\n\n\n\n<p><code>substr<\/code>\u3068<code>mb_substr<\/code>\u306e\u6700\u3082\u91cd\u8981\u306a\u9055\u3044\u306f\u3001\u6587\u5b57\u5217\u306e\u51e6\u7406\u5358\u4f4d\u306b\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>substr<\/strong>: \u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u6587\u5b57\u5217\u3092\u51e6\u7406<\/li>\n\n\n\n<li><strong>mb_substr<\/strong>: \u6587\u5b57\u5358\u4f4d\u3067\u6587\u5b57\u5217\u3092\u51e6\u7406<\/li>\n<\/ul>\n\n\n\n<p>\u3053\u306e\u9055\u3044\u306f\u3001\u7279\u306bUTF-8\u306a\u3069\u306e\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u30bb\u30c3\u30c8\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u306b\u9855\u8457\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u65e5\u672c\u8a9e\u306e\u4f8b\n$text = \"\u3053\u3093\u306b\u3061\u306f\u4e16\u754c\";\n\n\/\/ substr - \u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u51e6\u7406\uff08UTF-8\u3067\u306f\u65e5\u672c\u8a9e1\u6587\u5b57=3\u30d0\u30a4\u30c8\u7a0b\u5ea6\uff09\necho substr($text, 0, 3);  \/\/ \u51fa\u529b: \u3053\uff08\u306e\u4e00\u90e8\u3001\u6587\u5b57\u5316\u3051\u3059\u308b\u53ef\u80fd\u6027\u3042\u308a\uff09\n\n\/\/ mb_substr - \u6587\u5b57\u5358\u4f4d\u3067\u51e6\u7406\necho mb_substr($text, 0, 3, 'UTF-8');  \/\/ \u51fa\u529b: \u3053\u3093\u306b\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-63\">\u69cb\u6587\u306e\u9055\u3044<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ substr\u69cb\u6587\nstring substr(string $string, int $offset, ?int $length = null)\n\n\/\/ mb_substr\u69cb\u6587\nstring mb_substr(string $string, int $offset, ?int $length = null, ?string $encoding = null)\n<\/pre>\n\n\n\n<p><code>mb_substr<\/code>\u306b\u306f\u6587\u5b57\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3092\u6307\u5b9a\u3059\u308b\u7b2c4\u5f15\u6570\u304c\u3042\u308a\u307e\u3059\u3002\u7701\u7565\u3057\u305f\u5834\u5408\u306f<code>mb_internal_encoding()<\/code>\u3067\u8a2d\u5b9a\u3055\u308c\u305f\u30c7\u30d5\u30a9\u30eb\u30c8\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u304c\u4f7f\u7528\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-64\">\u4f7f\u3044\u5206\u3051\u306e\u57fa\u6e96<\/h4>\n\n\n<div id=\"id-02e39e4a-a7d1-42a4-aa39-4c0cc781de1c\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u72b6\u6cc1<\/th><th>\u63a8\u5968\u95a2\u6570<\/th><\/tr><\/thead><tbody><tr><td>\u7d14\u7c8b\u306aASCII\u6587\u5b57\u306e\u307f\uff08\u82f1\u6570\u5b57\u3001\u8a18\u53f7\uff09<\/td><td><code>substr<\/code>\uff08\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u9762\u3067\u6709\u5229\uff09<\/td><\/tr><tr><td>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\uff08\u65e5\u672c\u8a9e\u306a\u3069\uff09\u3092\u542b\u3080<\/td><td><code>mb_substr<\/code>\uff08\u6b63\u78ba\u6027\u512a\u5148\uff09<\/td><\/tr><tr><td>\u56fd\u969b\u5316\u5bfe\u5fdc\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3<\/td><td><code>mb_substr<\/code>\uff08\u5c06\u6765\u306e\u4e92\u63db\u6027\u78ba\u4fdd\uff09<\/td><\/tr><tr><td>\u9ad8\u901f\u51e6\u7406\u304c\u5fc5\u8981\u3067ASCII\u9650\u5b9a\u304c\u78ba\u5b9a<\/td><td><code>substr<\/code>\uff08\u7d043\u301c4\u500d\u9ad8\u901f\uff09<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\" id=\"i-65\">\u65e5\u672c\u8a9e\u306a\u3069\u306e\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6b63\u3057\u304f\u51e6\u7406\u3059\u308b\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u65e5\u672c\u8a9e\u51e6\u7406\u3067<code>substr<\/code>\u3092\u4f7f\u7528\u3059\u308b\u3068\u6b21\u306e\u3088\u3046\u306a\u554f\u984c\u304c\u767a\u751f\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6587\u5b57\u306e\u5207\u308c\u76ee\u304c\u4e0d\u6b63\u78ba<\/strong>: \u30d0\u30a4\u30c8\u5358\u4f4d\u3067\u5207\u308a\u53d6\u308b\u305f\u3081\u3001\u6587\u5b57\u306e\u9014\u4e2d\u3067\u5207\u308c\u3066\u6587\u5b57\u5316\u3051\u3059\u308b<\/li>\n\n\n\n<li><strong>\u6587\u5b57\u6570\u306e\u8a08\u7b97\u304c\u4e0d\u6b63\u78ba<\/strong>: <code>strlen()<\/code>\u306f\u30d0\u30a4\u30c8\u6570\u3092\u8fd4\u3059\u305f\u3081\u3001\u5b9f\u969b\u306e\u6587\u5b57\u6570\u3068\u4e00\u81f4\u3057\u306a\u3044<\/li>\n<\/ol>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-66\">\u6b63\u3057\u3044\u51e6\u7406\u306e\u4f8b<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$japaneseText = \"\u65e5\u672c\u8a9e\u30c6\u30ad\u30b9\u30c8\u306e\u4f8b\";\n\n\/\/ \u6587\u5b57\u6570\u306e\u30ab\u30a6\u30f3\u30c8\n$byteLength = strlen($japaneseText);       \/\/ UTF-8\u306a\u308939\u524d\u5f8c\uff08\u30d0\u30a4\u30c8\u6570\uff09\n$charLength = mb_strlen($japaneseText, 'UTF-8');  \/\/ 9\uff08\u6587\u5b57\u6570\uff09\n\necho \"\u30d0\u30a4\u30c8\u9577: $byteLength, \u6587\u5b57\u6570: $charLength\";\n\n\/\/ \u6587\u5b57\u5217\u306e\u4e00\u90e8\u3092\u53d6\u5f97\uff08\u5148\u982d\u304b\u30895\u6587\u5b57\uff09\n$substring = mb_substr($japaneseText, 0, 5, 'UTF-8');\necho $substring;  \/\/ \u51fa\u529b: \u65e5\u672c\u8a9e\u30c6\u30ad\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-67\">\u5b9f\u7528\u7684\u306a\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u5bfe\u5fdc\u95a2\u6570<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u9577\u3044\u30c6\u30ad\u30b9\u30c8\u3092\u5b89\u5168\u306b\u5207\u308a\u8a70\u3081\u308b\u95a2\u6570\nfunction truncateText($text, $length, $suffix = '...') {\n    if (mb_strlen($text, 'UTF-8') &lt;= $length) {\n        return $text;  \/\/ \u5341\u5206\u77ed\u3044\u5834\u5408\u306f\u305d\u306e\u307e\u307e\u8fd4\u3059\n    }\n    \n    return mb_substr($text, 0, $length, 'UTF-8') . $suffix;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$longText = \"\u3053\u308c\u306f\u975e\u5e38\u306b\u9577\u3044\u65e5\u672c\u8a9e\u306e\u30c6\u30ad\u30b9\u30c8\u3067\u3001\u9069\u5207\u306b\u5207\u308a\u8a70\u3081\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\";\necho truncateText($longText, 10);  \/\/ \u51fa\u529b: \u3053\u308c\u306f\u975e\u5e38\u306b\u9577\u3044...\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-68\">\u6587\u5b57\u30b3\u30fc\u30c9\u3092\u610f\u8b58\u3057\u305f\u5805\u7262\u306a\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3<\/h3>\n\n\n\n<p>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6271\u3046\u969b\u306f\u3001\u6587\u5b57\u30b3\u30fc\u30c9\uff08\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\uff09\u3092\u5e38\u306b\u610f\u8b58\u3059\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-69\">\u6587\u5b57\u30b3\u30fc\u30c9\u6307\u5b9a\u306e\u65b9\u6cd5<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u95a2\u6570\u547c\u3073\u51fa\u3057\u6642\u306b\u660e\u793a\u7684\u306b\u6307\u5b9a\uff08\u63a8\u5968\uff09<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">$result = mb_substr($text, 0, 5, 'UTF-8');\n<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>\u30b9\u30af\u30ea\u30d7\u30c8\u5185\u3067\u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u3092\u8a2d\u5b9a<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">mb_internal_encoding('UTF-8');\n$result = mb_substr($text, 0, 5);  \/\/ UTF-8\u3068\u3057\u3066\u51e6\u7406\n<\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>php.ini\u3067\u8a2d\u5b9a\uff08\u30b5\u30fc\u30d0\u30fc\u5168\u4f53\uff09<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">mbstring.internal_encoding = UTF-8\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-70\">\u5805\u7262\u306a\u5b9f\u88c5\u306e\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u4e00\u8cab\u3057\u305f\u6587\u5b57\u30b3\u30fc\u30c9\u51e6\u7406\u306e\u5b9f\u88c5<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u521d\u671f\u5316\u6642\nmb_internal_encoding('UTF-8');\nmb_http_output('UTF-8');\nmb_regex_encoding('UTF-8');\n\n\/\/ \u6587\u5b57\u5217\u51e6\u7406\u95a2\u6570\u3092\u30e9\u30c3\u30d7\u3057\u3066\u4e00\u8cab\u6027\u3092\u78ba\u4fdd\nfunction safeSubstring($text, $start, $length) {\n    if (!is_string($text)) {\n        return '';\n    }\n    return mb_substr($text, $start, $length, 'UTF-8');\n}\n<\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>mb_string\u95a2\u6570\u7fa4\u306e\u4e00\u8cab\u3057\u305f\u4f7f\u7528<\/strong><\/li>\n<\/ol>\n\n\n\n<p>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6271\u3046\u5834\u5408\u306f\u3001\u3059\u3079\u3066\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u3067\u5bfe\u5fdc\u3059\u308bmb_*\u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>strlen()<\/code> \u2192 <code>mb_strlen()<\/code><\/li>\n\n\n\n<li><code>strpos()<\/code> \u2192 <code>mb_strpos()<\/code><\/li>\n\n\n\n<li><code>strtolower()<\/code> \u2192 <code>mb_strtolower()<\/code><\/li>\n\n\n\n<li><code>substr()<\/code> \u2192 <code>mb_substr()<\/code><\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-71\">\u5b9f\u52d9\u3067\u306e\u6d3b\u7528\u4f8b<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u306e\u30e6\u30fc\u30b6\u30fc\u540d\u90e8\u5206\u3092\u53d6\u5f97\u3057\u30de\u30b9\u30ad\u30f3\u30b0\nfunction maskEmailUsername($email) {\n    $atPos = mb_strpos($email, '@', 0, 'UTF-8');\n    if ($atPos === false) {\n        return $email;  \/\/ @\u304c\u898b\u3064\u304b\u3089\u306a\u3044\u5834\u5408\n    }\n    \n    $username = mb_substr($email, 0, $atPos, 'UTF-8');\n    $domain = mb_substr($email, $atPos, null, 'UTF-8');\n    \n    \/\/ \u30e6\u30fc\u30b6\u30fc\u540d\u306e\u9577\u3055\u306b\u5fdc\u3058\u305f\u30de\u30b9\u30ad\u30f3\u30b0\n    $usernameLength = mb_strlen($username, 'UTF-8');\n    if ($usernameLength &lt;= 2) {\n        $maskedUsername = str_repeat('*', $usernameLength);\n    } else {\n        $maskedUsername = mb_substr($username, 0, 1, 'UTF-8') . \n                         str_repeat('*', $usernameLength - 2) . \n                         mb_substr($username, -1, 1, 'UTF-8');\n    }\n    \n    return $maskedUsername . $domain;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\necho maskEmailUsername(\"tanaka@example.com\");  \/\/ \u51fa\u529b: t*****a@example.com\necho maskEmailUsername(\"\u5c71\u7530\u592a\u90ce@example.jp\");  \/\/ \u51fa\u529b: \u5c71*****\u90ce@example.jp\n<\/pre>\n\n\n\n<p>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u3092\u6b63\u3057\u304f\u51e6\u7406\u3059\u308b\u306b\u306f<code>mb_substr<\/code>\u306e\u4f7f\u7528\u304c\u4e0d\u53ef\u6b20\u3067\u3059\u304c\u3001\u6ce8\u610f\u70b9\u3068\u3057\u3066<code>mbstring<\/code>\u62e1\u5f35\u30e2\u30b8\u30e5\u30fc\u30eb\u304c\u6709\u52b9\u306b\u306a\u3063\u3066\u3044\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002PHP\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u306b\u306f\u542b\u307e\u308c\u3066\u3044\u307e\u3059\u304c\u3001\u5ff5\u306e\u305f\u3081<code>phpinfo()<\/code>\u3067\u78ba\u8a8d\u3059\u308b\u3068\u3088\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<p>\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u5b9f\u52d9\u3067\u5373\u5f79\u7acb\u3064<code>substr<\/code>\u306e\u6d3b\u7528\u4f8b\u30927\u3064\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-72\">\u5b9f\u52d9\u3067\u4f7f\u3048\u308bPHP substr\u6d3b\u7528\u4f8b7\u9078<\/h2>\n\n\n\n<p>\u3053\u3053\u307e\u3067<code>substr<\/code>\u3068<code>mb_substr<\/code>\u306e\u57fa\u672c\u304b\u3089\u5fdc\u7528\u307e\u3067\u3092\u5b66\u3093\u3067\u304d\u307e\u3057\u305f\u3002\u3053\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u5b9f\u969b\u306e\u958b\u767a\u73fe\u5834\u3067\u3059\u3050\u306b\u5f79\u7acb\u3064\u5177\u4f53\u7684\u306a\u6d3b\u7528\u4f8b\u30927\u3064\u7d39\u4ecb\u3057\u307e\u3059\u3002\u5b9f\u969b\u306e\u30b3\u30fc\u30c9\u3068\u5171\u306b\u3001\u305d\u308c\u305e\u308c\u306e\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3\u3092\u89e3\u8aac\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-73\">Web\u30d5\u30a9\u30fc\u30e0\u304b\u3089\u306e\u5165\u529b\u5024\u3092\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u65b9\u6cd5<\/h3>\n\n\n\n<p>Web\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u306f\u3001\u30e6\u30fc\u30b6\u30fc\u304b\u3089\u9001\u4fe1\u3055\u308c\u305f\u30d5\u30a9\u30fc\u30e0\u5165\u529b\u3092\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002\u4ee5\u4e0b\u306f\u5165\u529b\u5024\u306e\u9577\u3055\u5236\u9650\u3068\u30de\u30b9\u30ad\u30f3\u30b0\u51e6\u7406\u306e\u4f8b\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-74\">\u5165\u529b\u6587\u5b57\u6570\u306e\u5236\u9650\u3068\u5207\u308a\u8a70\u3081<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function limitInput($input, $maxLength = 255) {\n  \/\/ \u5165\u529b\u5024\u304c\u7a7a\u3067\u306a\u3044\u3053\u3068\u3092\u78ba\u8a8d\n  if (empty($input)) {\n    return '';\n  }\n  \n  \/\/ \u6539\u884c\u3068\u30bf\u30d6\u3092\u30b9\u30da\u30fc\u30b9\u306b\u5909\u63db\n  $input = str_replace([\"\\r\\n\", \"\\r\", \"\\n\", \"\\t\"], ' ', $input);\n  \n  \/\/ \u6307\u5b9a\u3055\u308c\u305f\u9577\u3055\u306b\u6587\u5b57\u5217\u3092\u5207\u308a\u8a70\u3081\u308b\uff08\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u5bfe\u5fdc\uff09\n  if (mb_strlen($input, 'UTF-8') &gt; $maxLength) {\n    return mb_substr($input, 0, $maxLength, 'UTF-8') . '...';\n  }\n  \n  return $input;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$userComment = $_POST['comment'] ?? '';\n$safeComment = limitInput($userComment, 200);\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306f\u3001\u30e6\u30fc\u30b6\u30fc\u306e\u30b3\u30e1\u30f3\u30c8\u3084\u30e1\u30c3\u30bb\u30fc\u30b8\u306a\u3069\u306e\u5165\u529b\u3092\u5b89\u5168\u306a\u9577\u3055\u306b\u5236\u9650\u3057\u307e\u3059\u3002\u65e5\u672c\u8a9e\u306a\u3069\u306e\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u6587\u5b57\u306b\u3082\u5bfe\u5fdc\u3057\u3066\u304a\u308a\u3001\u6307\u5b9a\u3057\u305f\u6587\u5b57\u6570\u3092\u8d85\u3048\u308b\u5834\u5408\u306f\u81ea\u52d5\u7684\u306b\u5207\u308a\u8a70\u3081\u3066\u300c\u2026\u300d\u3092\u8ffd\u52a0\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-75\">\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u306e\u691c\u7d22\u7d50\u679c\u3092\u6700\u9069\u306b\u8868\u793a\u3059\u308b\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>\u691c\u7d22\u6a5f\u80fd\u3092\u5b9f\u88c5\u3059\u308b\u969b\u3001\u691c\u7d22\u7d50\u679c\u3092\u52b9\u679c\u7684\u306b\u8868\u793a\u3059\u308b\u305f\u3081\u306b\u306f\u3001\u95a2\u9023\u90e8\u5206\u3092\u62bd\u51fa\u3057\u3066\u8868\u793a\u3059\u308b\u30b9\u30cb\u30da\u30c3\u30c8\u751f\u6210\u304c\u6709\u52b9\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-76\">\u691c\u7d22\u7d50\u679c\u306e\u30b9\u30cb\u30da\u30c3\u30c8\u751f\u6210<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function generateSearchSnippet($content, $keyword, $snippetLength = 160) {\n  \/\/ \u691c\u7d22\u30ad\u30fc\u30ef\u30fc\u30c9\u304c\u542b\u307e\u308c\u3066\u3044\u308b\u304b\u78ba\u8a8d\uff08\u5927\u6587\u5b57\u5c0f\u6587\u5b57\u3092\u533a\u5225\u3057\u306a\u3044\uff09\n  $keywordPos = mb_stripos($content, $keyword, 0, 'UTF-8');\n  \n  if ($keywordPos !== false) {\n    \/\/ \u30ad\u30fc\u30ef\u30fc\u30c9\u306e\u524d\u5f8c\u306e\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3092\u53d6\u5f97\n    $startPos = max(0, $keywordPos - floor($snippetLength \/ 2));\n    \n    \/\/ \u30b9\u30cb\u30da\u30c3\u30c8\u3092\u62bd\u51fa\n    $snippet = mb_substr($content, $startPos, $snippetLength, 'UTF-8');\n    \n    \/\/ \u30b9\u30cb\u30da\u30c3\u30c8\u306e\u5148\u982d\u3068\u672b\u5c3e\u3092\u8abf\u6574\n    if ($startPos &gt; 0) {\n      $snippet = '...' . $snippet;\n    }\n    \n    if ($startPos + $snippetLength &lt; mb_strlen($content, 'UTF-8')) {\n      $snippet .= '...';\n    }\n    \n    return $snippet;\n  }\n  \n  \/\/ \u30ad\u30fc\u30ef\u30fc\u30c9\u304c\u898b\u3064\u304b\u3089\u306a\u3044\u5834\u5408\u306f\u5148\u982d\u304b\u3089\u8868\u793a\n  return mb_substr($content, 0, $snippetLength, 'UTF-8') . \n         (mb_strlen($content, 'UTF-8') &gt; $snippetLength ? '...' : '');\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$articles = [\n  ['id' =&gt; 1, 'title' =&gt; '\u5165\u9580PHP', 'content' =&gt; '\u521d\u5fc3\u8005\u5411\u3051\u306ePHP\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u89e3\u8aac...'],\n  ['id' =&gt; 2, 'title' =&gt; '\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u9023\u643a', 'content' =&gt; 'PHP\u304b\u3089MySQL\u3092\u64cd\u4f5c\u3059\u308b\u65b9\u6cd5...']\n];\n\n$searchResults = [];\n$keyword = 'PHP';\n\nforeach ($articles as $article) {\n  if (stripos($article['title'], $keyword) !== false || \n      stripos($article['content'], $keyword) !== false) {\n    $article['snippet'] = generateSearchSnippet($article['content'], $keyword);\n    $searchResults[] = $article;\n  }\n}\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306f\u9577\u3044\u30b3\u30f3\u30c6\u30f3\u30c4\u304b\u3089\u691c\u7d22\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u542b\u3080\u90e8\u5206\u3092\u62bd\u51fa\u3057\u3001\u524d\u5f8c\u306e\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3068\u5171\u306b\u8868\u793a\u3057\u307e\u3059\u3002\u691c\u7d22\u7d50\u679c\u30da\u30fc\u30b8\u3067\u691c\u7d22\u8a9e\u304c\u542b\u307e\u308c\u308b\u6587\u8108\u3092\u30e6\u30fc\u30b6\u30fc\u306b\u793a\u3059\u306e\u306b\u6700\u9069\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-77\">API\u30ec\u30b9\u30dd\u30f3\u30b9\u306e\u6587\u5b57\u5217\u3092\u52b9\u7387\u7684\u306b\u52a0\u5de5\u3059\u308b\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u5916\u90e8API\u3068\u9023\u643a\u3059\u308b\u969b\u3001\u30ec\u30b9\u30dd\u30f3\u30b9\u30c7\u30fc\u30bf\u3092\u9069\u5207\u306b\u51e6\u7406\u3059\u308b\u3053\u3068\u304c\u5fc5\u8981\u3067\u3059\u3002\u4ee5\u4e0b\u306fHTTP\u30ec\u30b9\u30dd\u30f3\u30b9\u3092\u89e3\u6790\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-78\">HTTP\u30ec\u30b9\u30dd\u30f3\u30b9\u306e\u30d8\u30c3\u30c0\u30fc\u3068\u30dc\u30c7\u30a3\u5206\u96e2<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function parseHttpResponse($response) {\n  \/\/ \u30d8\u30c3\u30c0\u30fc\u3068\u30dc\u30c7\u30a3\u306e\u5883\u754c\u3092\u691c\u7d22\n  $headerEnd = strpos($response, \"\\r\\n\\r\\n\");\n  \n  if ($headerEnd === false) {\n    return ['headers' =&gt; $response, 'body' =&gt; ''];\n  }\n  \n  \/\/ \u30d8\u30c3\u30c0\u30fc\u90e8\u5206\u3068\u30dc\u30c7\u30a3\u90e8\u5206\u3092\u5206\u96e2\n  $headers = substr($response, 0, $headerEnd);\n  $body = substr($response, $headerEnd + 4); \/\/ \\r\\n\\r\\n\u306e\u9577\u3055(4)\u3092\u8003\u616e\n  \n  \/\/ \u30d8\u30c3\u30c0\u30fc\u3092\u89e3\u6790\n  $headerLines = explode(\"\\r\\n\", $headers);\n  $parsedHeaders = [];\n  \n  foreach ($headerLines as $line) {\n    if (strpos($line, ':') !== false) {\n      list($key, $value) = explode(':', $line, 2);\n      $parsedHeaders[trim($key)] = trim($value);\n    }\n  }\n  \n  return [\n    'headers' =&gt; $parsedHeaders,\n    'body' =&gt; $body\n  ];\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$rawResponse = file_get_contents('http:\/\/example.com\/api', false, $context);\n$parsed = parseHttpResponse($rawResponse);\n$contentType = $parsed['headers']['Content-Type'] ?? '';\n$responseData = $parsed['body'];\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306fHTTP\u30ec\u30b9\u30dd\u30f3\u30b9\u3092\u30d8\u30c3\u30c0\u30fc\u90e8\u5206\u3068\u30dc\u30c7\u30a3\u90e8\u5206\u306b\u5206\u96e2\u3057\u307e\u3059\u3002\u4f4e\u30ec\u30d9\u30eb\u306eHTTP\u901a\u4fe1\u3092\u884c\u3046\u5834\u5408\u3084\u3001cURL\u306e\u30aa\u30d7\u30b7\u30e7\u30f3\u306b\u3088\u3063\u3066\u306f\u30d8\u30c3\u30c0\u30fc\u3068\u30dc\u30c7\u30a3\u304c\u4e00\u7dd2\u306b\u8fd4\u3055\u308c\u308b\u3053\u3068\u304c\u3042\u308a\u3001\u305d\u306e\u5834\u5408\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-79\">\u30d5\u30a1\u30a4\u30eb\u5165\u51fa\u529b\u306b\u304a\u3051\u308b\u6587\u5b57\u5217\u51e6\u7406\u306e\u5b9f\u88c5\u4f8b<\/h3>\n\n\n\n<p>\u30d5\u30a1\u30a4\u30eb\u51e6\u7406\u3067\u306f\u3001\u5927\u304d\u306a\u30d5\u30a1\u30a4\u30eb\u304b\u3089\u7279\u5b9a\u90e8\u5206\u306e\u307f\u3092\u52b9\u7387\u7684\u306b\u62bd\u51fa\u3059\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-80\">\u30ed\u30b0\u30d5\u30a1\u30a4\u30eb\u304b\u3089\u7279\u5b9a\u6642\u9593\u5e2f\u306e\u30a8\u30f3\u30c8\u30ea\u3092\u62bd\u51fa<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function extractLogEntriesByTimeRange($logFile, $startTime, $endTime) {\n  $startTimestamp = strtotime($startTime);\n  $endTimestamp = strtotime($endTime);\n  $entries = [];\n  \n  if (!file_exists($logFile)) {\n    return $entries;\n  }\n  \n  $handle = fopen($logFile, 'r');\n  if ($handle) {\n    while (($line = fgets($handle)) !== false) {\n      \/\/ \u30ed\u30b0\u306e\u65e5\u6642\u90e8\u5206\u3092\u62bd\u51fa\uff08\u4f8b: [2023-05-15 14:30:25]\uff09\n      if (preg_match('\/\\[([\\d-]+ [\\d:]+)\\]\/', $line, $matches)) {\n        $logTime = $matches[1];\n        $logTimestamp = strtotime($logTime);\n        \n        \/\/ \u6307\u5b9a\u3055\u308c\u305f\u6642\u9593\u7bc4\u56f2\u5185\u304b\u30c1\u30a7\u30c3\u30af\n        if ($logTimestamp &gt;= $startTimestamp &amp;&amp; $logTimestamp &lt;= $endTimestamp) {\n          $entries[] = $line;\n        }\n      }\n    }\n    \n    fclose($handle);\n  }\n  \n  return $entries;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$errors = extractLogEntriesByTimeRange(\n  '\/var\/log\/application.log',\n  '2023-05-15 10:00:00',\n  '2023-05-15 11:00:00'\n);\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306f\u5927\u304d\u306a\u30ed\u30b0\u30d5\u30a1\u30a4\u30eb\u304b\u3089\u7279\u5b9a\u306e\u6642\u9593\u7bc4\u56f2\u5185\u306e\u30a8\u30f3\u30c8\u30ea\u306e\u307f\u3092\u62bd\u51fa\u3057\u307e\u3059\u3002\u30b7\u30b9\u30c6\u30e0\u969c\u5bb3\u306e\u8abf\u67fb\u3084\u7279\u5b9a\u671f\u9593\u306e\u30a2\u30af\u30bb\u30b9\u89e3\u6790\u306a\u3069\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-81\">URL\u30d1\u30e9\u30e1\u30fc\u30bf\u306e\u89e3\u6790\u3068\u51e6\u7406\u306b\u304a\u3051\u308b\u6d3b\u7528\u6cd5<\/h3>\n\n\n\n<p>Web\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u306f\u3001URL\u306e\u89e3\u6790\u3068\u51e6\u7406\u304c\u983b\u7e41\u306b\u5fc5\u8981\u306b\u306a\u308a\u307e\u3059\u3002\u4ee5\u4e0b\u306fURL\u3092\u8868\u793a\u7528\u306b\u6574\u5f62\u3059\u308b\u4f8b\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-82\">URL\u3092\u6b63\u898f\u5316\u3057\u3066\u77ed\u7e2e\u8868\u793a<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function formatDisplayUrl($url, $maxLength = 40) {\n  \/\/ \u30b9\u30ad\u30fc\u30e0\uff08http:\/\/, https:\/\/\uff09\u3092\u9664\u53bb\n  $displayUrl = preg_replace('#^https?:\/\/#', '', $url);\n  \n  \/\/ www.\u304c\u5148\u982d\u306b\u3042\u308b\u5834\u5408\u306f\u9664\u53bb\n  $displayUrl = preg_replace('#^www\\.#', '', $displayUrl);\n  \n  \/\/ \u672b\u5c3e\u306e\u30b9\u30e9\u30c3\u30b7\u30e5\u3092\u9664\u53bb\n  $displayUrl = rtrim($displayUrl, '\/');\n  \n  \/\/ \u9577\u3055\u304c\u5236\u9650\u3092\u8d85\u3048\u308b\u5834\u5408\u306f\u5207\u308a\u8a70\u3081\n  if (strlen($displayUrl) &gt; $maxLength) {\n    $displayUrl = substr($displayUrl, 0, $maxLength - 3) . '...';\n  }\n  \n  return $displayUrl;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$urls = [\n  'https:\/\/www.example.com\/',\n  'https:\/\/developer.example.org\/documentation\/api\/reference\/v2\/',\n  'http:\/\/very-long-subdomain.example.net\/path\/to\/resource.html'\n];\n\nforeach ($urls as $url) {\n  echo formatDisplayUrl($url) . \"\\n\";\n}\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306fURL\u3092\u8868\u793a\u7528\u306b\u6574\u5f62\u3057\u3001\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u77ed\u7e2e\u3057\u307e\u3059\u3002\u691c\u7d22\u7d50\u679c\u3084\u53c2\u7167\u30ea\u30f3\u30af\u306e\u8868\u793a\u306b\u304a\u3044\u3066\u3001\u9650\u3089\u308c\u305f\u30b9\u30da\u30fc\u30b9\u3092\u52b9\u7387\u7684\u306b\u4f7f\u3046\u306e\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-83\">\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u5bfe\u7b56\u3068\u3057\u3066\u306e\u6587\u5b57\u5217\u691c\u8a3c\u3067\u306e\u4f7f\u3044\u65b9<\/h3>\n\n\n\n<p>\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u9762\u3067\u306f\u3001\u5165\u529b\u5024\u306e\u691c\u8a3c\u3084\u6a5f\u5bc6\u60c5\u5831\u306e\u4fdd\u8b77\u306b<code>substr<\/code>\u304c\u6d3b\u7528\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-84\">\u6a5f\u5bc6\u60c5\u5831\u306e\u30de\u30b9\u30ad\u30f3\u30b0\u51e6\u7406<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function maskSensitiveData($text, $patterns = []) {\n  \/\/ \u30c7\u30d5\u30a9\u30eb\u30c8\u306e\u691c\u51fa\u30d1\u30bf\u30fc\u30f3\n  $defaultPatterns = [\n    \/\/ \u30af\u30ec\u30b8\u30c3\u30c8\u30ab\u30fc\u30c9\u756a\u53f7\n    '\/\\b(?:\\d[ -]*?){13,16}\\b\/' =&gt; function($match) {\n      return substr($match[0], 0, 4) . ' **** **** ' . substr($match[0], -4);\n    },\n    \/\/ \u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\n    '\/[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}\/' =&gt; function($match) {\n      $parts = explode('@', $match[0]);\n      $name = $parts[0];\n      $domain = $parts[1];\n      return substr($name, 0, 1) . '***' . substr($name, -1) . '@' . $domain;\n    }\n  ];\n  \n  \/\/ \u30ab\u30b9\u30bf\u30e0\u30d1\u30bf\u30fc\u30f3\u3092\u8ffd\u52a0\n  $patterns = array_merge($defaultPatterns, $patterns);\n  \n  \/\/ \u5404\u30d1\u30bf\u30fc\u30f3\u306b\u5bfe\u3057\u3066\u51e6\u7406\n  foreach ($patterns as $pattern =&gt; $replacement) {\n    if (is_callable($replacement)) {\n      $text = preg_replace_callback($pattern, $replacement, $text);\n    } else {\n      $text = preg_replace($pattern, $replacement, $text);\n    }\n  }\n  \n  return $text;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$userInput = \"\u79c1\u306e\u9023\u7d61\u5148\u306ftanaka.taro@example.com\u3001\u30af\u30ec\u30b8\u30c3\u30c8\u30ab\u30fc\u30c9\u306f4111-2222-3333-4444\u3067\u3059\u3002\";\n$safeToPrint = maskSensitiveData($userInput);\n\/\/ \u51fa\u529b: \"\u79c1\u306e\u9023\u7d61\u5148\u306ft***a@example.com\u3001\u30af\u30ec\u30b8\u30c3\u30c8\u30ab\u30fc\u30c9\u306f4111 **** **** 4444\u3067\u3059\u3002\"\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306f\u30c6\u30ad\u30b9\u30c8\u5185\u306e\u6a5f\u5bc6\u60c5\u5831\uff08\u30af\u30ec\u30b8\u30c3\u30c8\u30ab\u30fc\u30c9\u756a\u53f7\u3001\u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u306a\u3069\uff09\u3092\u691c\u51fa\u3057\u3001\u90e8\u5206\u7684\u306b\u30de\u30b9\u30ad\u30f3\u30b0\u3057\u307e\u3059\u3002\u30ed\u30b0\u30d5\u30a1\u30a4\u30eb\u3084\u30c7\u30d0\u30c3\u30b0\u51fa\u529b\u306a\u3069\u306b\u6a5f\u5bc6\u60c5\u5831\u304c\u542b\u307e\u308c\u306a\u3044\u3088\u3046\u306b\u3059\u308b\u306e\u306b\u6709\u52b9\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-85\">\u30ed\u30b0\u30c7\u30fc\u30bf\u306e\u89e3\u6790\u3068\u52a0\u5de5\u306b\u304a\u3051\u308b\u5b9f\u7528\u30d1\u30bf\u30fc\u30f3<\/h3>\n\n\n\n<p>\u6700\u5f8c\u306b\u3001\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u30ed\u30b0\u306e\u89e3\u6790\u306b\u304a\u3051\u308bsubstr\u306e\u6d3b\u7528\u4f8b\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-86\">\u30a8\u30e9\u30fc\u30ed\u30b0\u306e\u30b5\u30de\u30ea\u30fc\u751f\u6210<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function generateErrorSummary($errorLog, $limit = 100) {\n  $errors = [];\n  $errorCounts = [];\n  \n  if (!file_exists($errorLog)) {\n    return ['errors' =&gt; [], 'summary' =&gt; []];\n  }\n  \n  $handle = fopen($errorLog, 'r');\n  if ($handle) {\n    while (($line = fgets($handle)) !== false) {\n      \/\/ \u30a8\u30e9\u30fc\u30bf\u30a4\u30d7\u3092\u62bd\u51fa\uff08\u4f8b: PHP Fatal error: \u306a\u3069\uff09\n      if (preg_match('\/^\\[([\\d-]+) ([\\d:]+)\\] (PHP [A-Za-z]+ error:)(.+) in (.+) on line (\\d+)$\/', $line, $matches)) {\n        $date = $matches[1];\n        $time = $matches[2];\n        $errorType = $matches[3];\n        $message = trim($matches[4]);\n        $file = $matches[5];\n        $line = $matches[6];\n        \n        \/\/ \u30a8\u30e9\u30fc\u306e\u6982\u8981\u3092\u4f5c\u6210\uff08\u30bf\u30a4\u30d7\u3068\u30e1\u30c3\u30bb\u30fc\u30b8\uff09\n        $errorSummary = $errorType . ' ' . substr($message, 0, 100) . \n                        (strlen($message) &gt; 100 ? '...' : '');\n        \n        \/\/ \u30a8\u30e9\u30fc\u6570\u3092\u30ab\u30a6\u30f3\u30c8\n        if (!isset($errorCounts[$errorSummary])) {\n          $errorCounts[$errorSummary] = [\n            'count' =&gt; 0,\n            'last_seen' =&gt; null,\n            'file' =&gt; $file,\n            'line' =&gt; $line\n          ];\n        }\n        \n        $errorCounts[$errorSummary]['count']++;\n        $errorCounts[$errorSummary]['last_seen'] = $date . ' ' . $time;\n        \n        \/\/ \u8a73\u7d30\u306a\u30a8\u30e9\u30fc\u60c5\u5831\u3092\u8a18\u9332\uff08\u4e0a\u9650\u307e\u3067\uff09\n        if (count($errors) &lt; $limit) {\n          $errors[] = [\n            'datetime' =&gt; $date . ' ' . $time,\n            'type' =&gt; $errorType,\n            'message' =&gt; $message,\n            'file' =&gt; $file,\n            'line' =&gt; $line\n          ];\n        }\n      }\n    }\n    \n    fclose($handle);\n  }\n  \n  \/\/ \u30a8\u30e9\u30fc\u6570\u3067\u964d\u9806\u30bd\u30fc\u30c8\n  arsort($errorCounts);\n  \n  return [\n    'errors' =&gt; $errors,  \/\/ \u8a73\u7d30\u306a\u30a8\u30e9\u30fc\u30ea\u30b9\u30c8\n    'summary' =&gt; $errorCounts  \/\/ \u30a8\u30e9\u30fc\u30bf\u30a4\u30d7\u3054\u3068\u306e\u96c6\u8a08\n  ];\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$errorSummary = generateErrorSummary('\/var\/log\/php_errors.log');\nforeach ($errorSummary['summary'] as $error =&gt; $details) {\n  echo $error . \" - \" . $details['count'] . \"\u56de\u767a\u751f\uff08\u6700\u7d42: \" . $details['last_seen'] . \"\uff09\\n\";\n}\n<\/pre>\n\n\n\n<p>\u3053\u306e\u95a2\u6570\u306fPHP\u30a8\u30e9\u30fc\u30ed\u30b0\u30d5\u30a1\u30a4\u30eb\u3092\u89e3\u6790\u3057\u3001\u30a8\u30e9\u30fc\u30bf\u30a4\u30d7\u3054\u3068\u306e\u767a\u751f\u56de\u6570\u3068\u6700\u7d42\u767a\u751f\u6642\u523b\u3092\u96c6\u8a08\u3057\u307e\u3059\u3002\u9577\u3044\u30a8\u30e9\u30fc\u30e1\u30c3\u30bb\u30fc\u30b8\u306f<code>substr<\/code>\u3067\u9069\u5207\u306a\u9577\u3055\u306b\u5207\u308a\u8a70\u3081\u3089\u308c\u3001\u898b\u3084\u3059\u3044\u30b5\u30de\u30ea\u30fc\u304c\u751f\u6210\u3055\u308c\u307e\u3059\u3002\u5927\u91cf\u306e\u30a8\u30e9\u30fc\u30ed\u30b0\u304b\u3089\u91cd\u8981\u306a\u60c5\u5831\u3092\u7d20\u65e9\u304f\u628a\u63e1\u3059\u308b\u306e\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4ee5\u4e0a\u306e7\u3064\u306e\u5b9f\u88c5\u4f8b\u3092\u901a\u3058\u3066\u3001<code>substr<\/code>\u3068<code>mb_substr<\/code>\u304c\u3044\u304b\u306b\u5b9f\u52d9\u3067\u6d3b\u7528\u3067\u304d\u308b\u304b\u3092\u7d39\u4ecb\u3057\u307e\u3057\u305f\u3002\u3053\u308c\u3089\u306e\u57fa\u672c\u7684\u306a\u6587\u5b57\u5217\u64cd\u4f5c\u95a2\u6570\u3092\u4f7f\u3044\u3053\u306a\u3059\u3053\u3068\u3067\u3001\u3088\u308a\u5805\u7262\u3067\u52b9\u7387\u7684\u306aPHP\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3092\u958b\u767a\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3055\u3089\u306b\u95a2\u9023\u3059\u308b\u6587\u5b57\u5217\u95a2\u6570\u3068\u306e\u9023\u643a\u306b\u3064\u3044\u3066\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-87\">\u95a2\u9023\u3059\u308b\u6587\u5b57\u5217\u95a2\u6570\u3068\u306e\u9023\u643a<\/h2>\n\n\n\n<p>PHP\u3067\u306f\u6587\u5b57\u5217\u64cd\u4f5c\u306e\u305f\u3081\u306e\u69d8\u3005\u306a\u95a2\u6570\u304c\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u304c\u3001\u305d\u308c\u3089\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u5f37\u529b\u306a\u51e6\u7406\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u306f<code>substr<\/code>\u3068\u4ed6\u306e\u6587\u5b57\u5217\u95a2\u6570\u3092\u9023\u643a\u3055\u305b\u308b\u65b9\u6cd5\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-88\">strpos\u3068substr\u3092\u7d44\u307f\u5408\u308f\u305b\u305f\u9ad8\u5ea6\u306a\u6587\u5b57\u5217\u64cd\u4f5c<\/h3>\n\n\n\n<p><code>strpos<\/code>\u3067\u6587\u5b57\u5217\u5185\u306e\u7279\u5b9a\u30d1\u30bf\u30fc\u30f3\u306e\u4f4d\u7f6e\u3092\u7279\u5b9a\u3057\u3001<code>substr<\/code>\u3067\u305d\u306e\u5468\u8fba\u306e\u30c6\u30ad\u30b9\u30c8\u3092\u62bd\u51fa\u3059\u308b\u7d44\u307f\u5408\u308f\u305b\u306f\u975e\u5e38\u306b\u5f37\u529b\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-89\">\u30c7\u30ea\u30df\u30bf\u3067\u533a\u5207\u3089\u308c\u305f\u90e8\u5206\u306e\u62bd\u51fa<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function extractBetween($string, $start, $end) {\n  $startPos = strpos($string, $start);\n  if ($startPos === false) {\n    return '';\n  }\n  \n  $startPos += strlen($start);\n  $endPos = strpos($string, $end, $startPos);\n  \n  if ($endPos === false) {\n    return substr($string, $startPos);\n  }\n  \n  return substr($string, $startPos, $endPos - $startPos);\n}\n\n\/\/ \u4f7f\u7528\u4f8b\uff1aHTML\u30bf\u30b0\u306e\u4e2d\u8eab\u3092\u62bd\u51fa\n$html = '&lt;title&gt;PHP\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u5165\u9580&lt;\/title&gt;';\n$title = extractBetween($html, '&lt;title&gt;', '&lt;\/title&gt;'); \/\/ \u7d50\u679c: PHP\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u5165\u9580\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-90\">\u30d5\u30a1\u30a4\u30eb\u62e1\u5f35\u5b50\u306e\u53d6\u5f97<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function getFileExtension($filename) {\n  $dotPos = strrpos($filename, '.');\n  if ($dotPos === false) {\n    return '';\n  }\n  \n  return substr($filename, $dotPos + 1);\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$filename = 'report.2023.pdf';\n$extension = getFileExtension($filename); \/\/ \u7d50\u679c: pdf\n<\/pre>\n\n\n\n<p><code>strrpos<\/code>\u3092\u4f7f\u3046\u3053\u3068\u3067\u3001\u6700\u5f8c\u306e\u30d4\u30ea\u30aa\u30c9\u306e\u4f4d\u7f6e\u3092\u898b\u3064\u3051\u3001\u78ba\u5b9f\u306b\u62e1\u5f35\u5b50\u3092\u62bd\u51fa\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-91\">str_replace\u3068\u306e\u4f7f\u3044\u5206\u3051\u3067\u5b9f\u73fe\u3059\u308b\u67d4\u8edf\u306a\u30c6\u30ad\u30b9\u30c8\u52a0\u5de5<\/h3>\n\n\n\n<p><code>substr<\/code>\u306f\u4f4d\u7f6e\u6307\u5b9a\u306b\u3088\u308b\u62bd\u51fa\u306b\u5411\u3044\u3066\u304a\u308a\u3001<code>str_replace<\/code>\u306f\u30d1\u30bf\u30fc\u30f3\u30d9\u30fc\u30b9\u306e\u7f6e\u63db\u306b\u9069\u3057\u3066\u3044\u307e\u3059\u3002\u72b6\u6cc1\u306b\u5fdc\u3058\u3066\u4f7f\u3044\u5206\u3051\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-92\">\u6587\u5b57\u5217\u306e\u90e8\u5206\u7684\u306a\u7f6e\u63db<\/h4>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">function maskCreditCard($cardNumber) {\n  \/\/ \u6700\u521d\u306e4\u6841\u3068\u6700\u5f8c\u306e4\u6841\u4ee5\u5916\u3092\u30de\u30b9\u30af\n  if (strlen($cardNumber) &lt; 8) {\n    return str_repeat('*', strlen($cardNumber));\n  }\n  \n  $firstPart = substr($cardNumber, 0, 4);\n  $lastPart = substr($cardNumber, -4);\n  $middleLength = strlen($cardNumber) - 8;\n  \n  return $firstPart . str_repeat('*', $middleLength) . $lastPart;\n}\n\n\/\/ \u4f7f\u7528\u4f8b\n$card = '4111222233334444';\necho maskCreditCard($card); \/\/ \u7d50\u679c: 4111********4444\n<\/pre>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306b\u3001<code>substr<\/code>\u3067\u6b8b\u3059\u90e8\u5206\u3092\u53d6\u308a\u51fa\u3057\u3001<code>str_repeat<\/code>\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u67d4\u8edf\u306a\u30de\u30b9\u30ad\u30f3\u30b0\u51e6\u7406\u304c\u5b9f\u73fe\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-93\">\u6761\u4ef6\u4ed8\u304d\u7f6e\u63db\u3068\u306e\u4f7f\u3044\u5206\u3051<\/h4>\n\n\n\n<p>\u7279\u5b9a\u306e\u30d1\u30bf\u30fc\u30f3\u3092\u5225\u306e\u6587\u5b57\u5217\u306b\u7f6e\u304d\u63db\u3048\u308b\u5834\u5408\u306f<code>str_replace<\/code>\u304c\u9069\u3057\u3066\u3044\u307e\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u7279\u5b9a\u306e\u5358\u8a9e\u3092\u30de\u30b9\u30af\u3059\u308b\n$text = '\u30d1\u30b9\u30ef\u30fc\u30c9\u306f secret123 \u3067\u3059\u3002';\n$masked = str_replace('secret123', '********', $text);\n\n\/\/ \u8907\u6570\u306e\u30d1\u30bf\u30fc\u30f3\u3092\u4e00\u62ec\u7f6e\u63db\n$replacements = [\n  '\u30d1\u30b9\u30ef\u30fc\u30c9' =&gt; '\u8a8d\u8a3c\u30ad\u30fc',\n  'secret123' =&gt; '********'\n];\n$result = str_replace(array_keys($replacements), array_values($replacements), $text);\n<\/pre>\n\n\n\n<p>\u5bfe\u3057\u3066\u3001\u4f4d\u7f6e\u304c\u91cd\u8981\u306a\u5834\u5408\u306f<code>substr<\/code>\u3068\u4f4d\u7f6e\u7279\u5b9a\u95a2\u6570\u306e\u7d44\u307f\u5408\u308f\u305b\u304c\u9069\u3057\u3066\u3044\u307e\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u65e5\u4ed8\u5f62\u5f0f\u3092\u5909\u63db (YYYY-MM-DD \u2192 MM\/DD\/YYYY)\nfunction reformatDate($date) {\n  $year = substr($date, 0, 4);\n  $month = substr($date, 5, 2);\n  $day = substr($date, 8, 2);\n  return $month . '\/' . $day . '\/' . $year;\n}\n\n$date = '2023-05-15';\necho reformatDate($date); \/\/ \u7d50\u679c: 05\/15\/2023\n<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-94\">explode\u3068substr\u306e\u4f7f\u3044\u5206\u3051\u3068\u7d44\u307f\u5408\u308f\u305b\u6226\u7565<\/h3>\n\n\n\n<p><code>explode<\/code>\u306f\u30c7\u30ea\u30df\u30bf\u306b\u3088\u308b\u5206\u5272\u3001<code>substr<\/code>\u306f\u4f4d\u7f6e\u6307\u5b9a\u306b\u3088\u308b\u62bd\u51fa\u3092\u884c\u3044\u307e\u3059\u3002\u305d\u308c\u305e\u308c\u306e\u5f37\u307f\u3092\u6d3b\u304b\u3057\u305f\u4f7f\u3044\u5206\u3051\u304c\u91cd\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-95\">explode\u304c\u9069\u3057\u305f\u5834\u5408<\/h4>\n\n\n\n<p>\u660e\u78ba\u306a\u30c7\u30ea\u30df\u30bf\u304c\u3042\u308a\u3001\u305d\u308c\u306b\u3088\u3063\u3066\u5206\u5272\u3055\u308c\u305f\u5404\u90e8\u5206\u304c\u5fc5\u8981\u306a\u5834\u5408\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ CSV\u30c7\u30fc\u30bf\u3092\u89e3\u6790\n$csvLine = 'John,Doe,35,New York';\n$columns = explode(',', $csvLine);\n\/\/ \u7d50\u679c: ['John', 'Doe', '35', 'New York']\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-96\">substr\u304c\u9069\u3057\u305f\u5834\u5408<\/h4>\n\n\n\n<p>\u56fa\u5b9a\u9577\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u306e\u30c7\u30fc\u30bf\u3092\u6271\u3046\u5834\u5408\u3084\u3001\u4f4d\u7f6e\u304c\u91cd\u8981\u306a\u5834\u5408\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u56fa\u5b9a\u9577\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u306e\u30c7\u30fc\u30bf\uff08\u4f8b\uff1a\u90f5\u4fbf\u756a\u53f7\uff09\n$postalCode = '123-4567';\n$firstPart = substr($postalCode, 0, 3);  \/\/ 123\n$secondPart = substr($postalCode, 4);    \/\/ 4567\n<\/pre>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"i-97\">\u7d44\u307f\u5408\u308f\u305b\u6226\u7565<\/h4>\n\n\n\n<p>\u8907\u96d1\u306a\u30c7\u30fc\u30bf\u5f62\u5f0f\u3067\u306f\u3001\u4e21\u65b9\u306e\u95a2\u6570\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u52b9\u7387\u7684\u306b\u89e3\u6790\u3067\u304d\u307e\u3059\uff1a<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"generic\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ \u8907\u5408\u7684\u306a\u30c7\u30fc\u30bf\u5f62\u5f0f\u3092\u89e3\u6790\nfunction parseComplexData($data) {\n  $result = [];\n  $sections = explode(';', $data);\n  \n  foreach ($sections as $section) {\n    $equalsPos = strpos($section, '=');\n    if ($equalsPos !== false) {\n      $key = trim(substr($section, 0, $equalsPos));\n      $value = trim(substr($section, $equalsPos + 1));\n      $result[$key] = $value;\n    }\n  }\n  \n  return $result;\n}\n\n$data = 'name=John Doe; age=30; city=Tokyo';\n$parsed = parseComplexData($data);\n\/\/ \u7d50\u679c: ['name' =&gt; 'John Doe', 'age' =&gt; '30', 'city' =&gt; 'Tokyo']\n<\/pre>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306b\u3001PHP\u306e\u6587\u5b57\u5217\u95a2\u6570\u3092\u72b6\u6cc1\u306b\u5fdc\u3058\u3066\u9069\u5207\u306b\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u8907\u96d1\u306a\u6587\u5b57\u5217\u51e6\u7406\u3082\u52b9\u7387\u7684\u306b\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002\u9069\u6750\u9069\u6240\u3067\u95a2\u6570\u3092\u9078\u629e\u3057\u3001\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u4fdd\u5b88\u6027\u304c\u9ad8\u304f\u52b9\u7387\u7684\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-98\">\u307e\u3068\u3081<\/h2>\n\n\n\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001PHP\u306e\u6587\u5b57\u5217\u64cd\u4f5c\u306b\u304a\u3051\u308b\u57fa\u790e\u7684\u304b\u3064\u91cd\u8981\u306a\u95a2\u6570\u3067\u3042\u308b<code>substr<\/code>\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u89e3\u8aac\u3057\u3066\u304d\u307e\u3057\u305f\u3002\u6700\u5f8c\u306b\u5b66\u3093\u3060\u5185\u5bb9\u3092\u632f\u308a\u8fd4\u308a\u3001\u6b21\u306e\u30b9\u30c6\u30c3\u30d7\u306b\u3064\u3044\u3066\u8003\u3048\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-99\">\u8a18\u4e8b\u3067\u5b66\u3093\u3060\u5185\u5bb9\u306e\u5fa9\u7fd2\u3068\u307e\u3068\u3081<\/h3>\n\n\n\n<p><code>substr<\/code>\u95a2\u6570\u306f\u4e00\u898b\u30b7\u30f3\u30d7\u30eb\u3067\u3059\u304c\u3001\u591a\u304f\u306e\u53ef\u80fd\u6027\u3092\u79d8\u3081\u3066\u3044\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u57fa\u672c\u69cb\u6587<\/strong>: <code>string substr(string $string, int $offset, ?int $length = null)<\/code><\/li>\n\n\n\n<li><strong>\u67d4\u8edf\u306a\u30d1\u30e9\u30e1\u30fc\u30bf<\/strong>: \u6b63\u3068\u8ca0\u306e\u5024\u3092\u4f7f\u3044\u5206\u3051\u308b\u3053\u3068\u3067\u3001\u6587\u5b57\u5217\u306e\u5148\u982d\u3001\u4e2d\u9593\u3001\u672b\u5c3e\u3092\u81ea\u5728\u306b\u62bd\u51fa\u3067\u304d\u308b<\/li>\n\n\n\n<li><strong>\u30de\u30eb\u30c1\u30d0\u30a4\u30c8\u5bfe\u5fdc<\/strong>: \u65e5\u672c\u8a9e\u306a\u3069\u306e\u591a\u8a00\u8a9e\u51e6\u7406\u306b\u306f<code>mb_substr<\/code>\u3092\u4f7f\u3063\u3066\u30a8\u30f3\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u3092\u660e\u793a\u7684\u306b\u6307\u5b9a<\/li>\n\n\n\n<li><strong>\u30a8\u30e9\u30fc\u56de\u907f<\/strong>: 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class=\"wp-block-list\">\n<li>\u6761\u4ef6\u5206\u5c90\u3084\u30eb\u30fc\u30d7\u51e6\u7406\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\u306b\u3088\u308b\u9ad8\u5ea6\u306a\u6587\u5b57\u5217\u64cd\u4f5c<\/li>\n\n\n\n<li><code>strpos<\/code>\u3001<code>str_replace<\/code>\u3001<code>explode<\/code>\u306a\u3069\u306e\u4ed6\u306e\u6587\u5b57\u5217\u95a2\u6570\u3068\u306e\u9023\u643a\u6226\u7565<\/li>\n\n\n\n<li>Web\u30d5\u30a9\u30fc\u30e0\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3001API\u3001\u30ed\u30b0\u51e6\u7406\u306a\u3069\u5b9f\u52d9\u3067\u4f7f\u3048\u308b7\u3064\u306e\u5b9f\u88c5\u30d1\u30bf\u30fc\u30f3<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-100\">PHP substr\u30de\u30b9\u30bf\u30fc\u5f8c\u306e\u6b21\u306e\u30b9\u30c6\u30c3\u30d7<\/h3>\n\n\n\n<p><code>substr<\/code>\u3092\u30de\u30b9\u30bf\u30fc\u3057\u305f\u5f8c\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u3088\u308a\u9ad8\u5ea6\u306a\u30c8\u30d4\u30c3\u30af\u306b\u6311\u6226\u3057\u3066\u307f\u308b\u3053\u3068\u3092\u304a\u52e7\u3081\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u6b63\u898f\u8868\u73fe\u306e\u7fd2\u5f97<\/strong>: <code>preg_match()<\/code>\u3084<code>preg_replace()<\/code>\u306a\u3069\u3092\u4f7f\u3063\u305f\u8907\u96d1\u306a\u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u3068\u7f6e\u63db<\/li>\n\n\n\n<li><strong>\u6587\u5b57\u5217\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u7406\u89e3<\/strong>: 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8\u306e\u65b0\u6a5f\u80fd\u306b\u95a2\u3059\u308b\u66f8\u7c4d\u306a\u3069\u304c\u5f79\u7acb\u3061\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-101\">\u6587\u5b57\u5217\u51e6\u7406\u30b9\u30ad\u30eb\u5411\u4e0a\u306e\u305f\u3081\u306e\u5b9f\u8df5\u7684\u30a2\u30c9\u30d0\u30a4\u30b9<\/h3>\n\n\n\n<p>\u6700\u5f8c\u306b\u3001\u6587\u5b57\u5217\u51e6\u7406\u30b9\u30ad\u30eb\u3092\u5411\u4e0a\u3055\u305b\u308b\u305f\u3081\u306e\u5b9f\u8df5\u7684\u306a\u30a2\u30c9\u30d0\u30a4\u30b9\u3092\u3044\u304f\u3064\u304b\u7d39\u4ecb\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u3092\u9ad8\u3081\u308b<\/strong>: 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\/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/ &#8230; 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