{"id":1256,"date":"2025-03-24T08:52:29","date_gmt":"2025-03-23T23:52:29","guid":{"rendered":"https:\/\/dexall.co.jp\/articles\/?p=1256"},"modified":"2025-03-24T08:52:29","modified_gmt":"2025-03-23T23:52:29","slug":"%e3%80%90%e4%bf%9d%e5%ad%98%e7%89%88%e3%80%91ruby%e5%88%9d%e7%b4%9a%e8%80%85%e3%81%a7%e3%82%82%e3%81%99%e3%81%90%e3%81%ab%e7%90%86%e8%a7%a3%e3%81%a7%e3%81%8d%e3%82%8b%ef%bc%81%e3%82%af%e3%83%a9","status":"publish","type":"post","link":"https:\/\/dexall.co.jp\/articles\/?p=1256","title":{"rendered":"\u3010\u4fdd\u5b58\u7248\u3011Ruby\u521d\u7d1a\u8005\u3067\u3082\u3059\u3050\u306b\u7406\u89e3\u3067\u304d\u308b\uff01\u30af\u30e9\u30b9\u306e\u57fa\u672c\u3068\u5b9f\u8df5\u7684\u306a\u4f7f\u3044\u65b97\u9078"},"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\">Ruby\u306e\u30af\u30e9\u30b9\u3068\u306f\uff1f\u57fa\u790e\u304b\u3089\u5b8c\u5168\u306b\u7406\u89e3\u3059\u308b<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-1\">\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u306e\u4e16\u754c\u3067\u30af\u30e9\u30b9\u304c\u679c\u305f\u3059\u91cd\u8981\u306a\u5f79\u5272<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-2\">\u30af\u30e9\u30b9\u3068\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u95a2\u4fc2\u6027\u3092\u56f3\u89e3\u3067\u7406\u89e3<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-3\">\u30af\u30e9\u30b9\u306e\u4f5c\u308a\u65b9\u3092\u30de\u30b9\u30bf\u30fc\u3057\u3088\u3046<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-4\">\u30af\u30e9\u30b9\u5b9a\u7fa9\u306e\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3068\u547d\u540d\u898f\u5247<\/a>      <\/li>      <li>        <a href=\"#i-5\">\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u3068\u30af\u30e9\u30b9\u5909\u6570\u306e\u4f7f\u3044\u65b9<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-6\">\u30e1\u30bd\u30c3\u30c9\u5b9a\u7fa9\u3068\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\u306e\u91cd\u8981\u6027<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-7\">\u30af\u30e9\u30b9\u3092\u4f7f\u3044\u3053\u306a\u3059\u305f\u3081\u306e7\u3064\u306e\u5b9f\u8df5\u30c6\u30af\u30cb\u30c3\u30af<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-8\">\u7d99\u627f\u3092\u6d3b\u7528\u3057\u305f\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-9\">\u30e2\u30b8\u30e5\u30fc\u30eb\u3067\u30af\u30e9\u30b9\u306b\u6a5f\u80fd\u3092\u8ffd\u52a0\u3059\u308b<\/a>      <\/li>      <li>        <a href=\"#i-10\">\u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u3067\u5171\u901a\u51e6\u7406\u3092\u5b9f\u88c5\u3059\u308b<\/a>      <\/li>      <li>        <a href=\"#i-11\">initialize\u30e1\u30bd\u30c3\u30c9\u3067\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u521d\u671f\u5316\u3059\u308b<\/a>      <\/li>      <li>        <a href=\"#i-12\">attr_accessor\u3067\u308f\u304b\u308a\u3084\u3059\u3044\u30b3\u30fc\u30c9\u3092\u66f8\u304f<\/a>      <\/li>      <li>        <a href=\"#i-13\">private\u30e1\u30bd\u30c3\u30c9\u3067\u30ab\u30d7\u30bb\u30eb\u5316\u3092\u5b9f\u73fe\u3059\u308b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-14\">\u30af\u30e9\u30b9\u5b9a\u6570\u3092\u52b9\u679c\u7684\u306b\u4f7f\u7528\u3059\u308b<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-15\">\u8a2d\u8a08\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-16\">\u5358\u4e00\u8cac\u4efb\u306e\u539f\u5247\u306b\u57fa\u3065\u304f\u30af\u30e9\u30b9\u8a2d\u8a08<\/a>      <\/li>      <li>        <a href=\"#i-17\">\u6b63\u3057\u3044\u30af\u30e9\u30b9\u540d\u3067\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u6027\u3092\u9ad8\u3081\u308b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-18\">\u30c6\u30b9\u30c8\u3057\u3084\u3059\u3044\u30af\u30e9\u30b9\u306e\u4f5c\u308a\u65b9<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-19\">\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u89e3\u6c7a\u65b9\u6cd5<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-20\">NameError\u306e\u539f\u56e0\u3068\u5bfe\u51e6\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-21\">NoMethodError\u3092\u89e3\u6c7a\u3059\u308b\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-22\">\u30b9\u30b3\u30fc\u30d7\u95a2\u9023\u306e\u30c8\u30e9\u30d6\u30eb\u30b7\u30e5\u30fc\u30c6\u30a3\u30f3\u30b0<\/a>      <\/li>    <\/ul>  <\/li>  <li class=\"last\">    <a href=\"#i-23\">\u5b9f\u8df5\u7684\u306a\u30b3\u30fc\u30c9\u4f8b\u3067\u5b66\u3076\u30af\u30e9\u30b9\u306e\u6d3b\u7528<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-24\">\u30e6\u30fc\u30b6\u30fc\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u306e\u5b9f\u88c5\u4f8b<\/a>      <\/li>      <li>        <a href=\"#i-25\">\u5728\u5eab\u7ba1\u7406\u30af\u30e9\u30b9\u306e\u4f5c\u6210\u624b\u9806<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-26\">\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u5b66\u3076\u30c7\u30b6\u30a4\u30f3\u30d1\u30bf\u30fc\u30f3<\/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\">Ruby\u306e\u30af\u30e9\u30b9\u3068\u306f\uff1f\u57fa\u790e\u304b\u3089\u5b8c\u5168\u306b\u7406\u89e3\u3059\u308b<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-1\">\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u306e\u4e16\u754c\u3067\u30af\u30e9\u30b9\u304c\u679c\u305f\u3059\u91cd\u8981\u306a\u5f79\u5272<\/h3>\n\n\n\n<p>Ruby\u306f\u7d14\u7c8b\u306a\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u8a00\u8a9e\u3067\u3042\u308a\u3001\u305d\u306e\u4e2d\u5fc3\u306b\u3042\u308b\u306e\u304c\u300c\u30af\u30e9\u30b9\u300d\u3068\u3044\u3046\u6982\u5ff5\u3067\u3059\u3002\u30af\u30e9\u30b9\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u8a2d\u8a08\u56f3\u3084\u578b\u3092\u5b9a\u7fa9\u3059\u308b\u6a5f\u80fd\u3092\u6301\u3061\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u69cb\u9020\u5316\u3068\u518d\u5229\u7528\u6027\u3092\u9ad8\u3081\u308b\u91cd\u8981\u306a\u5f79\u5272\u3092\u679c\u305f\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u30af\u30e9\u30b9\u306e\u4e3b\u306a\u5f79\u5272\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u30c7\u30fc\u30bf\u3068\u632f\u308b\u821e\u3044\u306e\u4e00\u5143\u7ba1\u7406<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u6301\u3064\u30c7\u30fc\u30bf\uff08\u5c5e\u6027\uff09\u3068\u3001\u305d\u306e\u30c7\u30fc\u30bf\u3092\u64cd\u4f5c\u3059\u308b\u30e1\u30bd\u30c3\u30c9\uff08\u632f\u308b\u821e\u3044\uff09\u3092\u307e\u3068\u3081\u3066\u7ba1\u7406<\/li>\n\n\n\n<li>\u95a2\u9023\u3059\u308b\u6a5f\u80fd\u3092\u4e00\u3064\u306e\u5358\u4f4d\u3068\u3057\u3066\u6271\u3046\u3053\u3068\u304c\u53ef\u80fd<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u5411\u4e0a<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e00\u5ea6\u5b9a\u7fa9\u3057\u305f\u30af\u30e9\u30b9\u3092\u4f55\u5ea6\u3067\u3082\u5229\u7528\u53ef\u80fd<\/li>\n\n\n\n<li>\u540c\u3058\u3088\u3046\u306a\u6a5f\u80fd\u3092\u6301\u3064\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u52b9\u7387\u7684\u306b\u4f5c\u6210<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u69cb\u9020\u5316<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u6a5f\u80fd\u3054\u3068\u306b\u9069\u5207\u306a\u5206\u5272\u304c\u53ef\u80fd<\/li>\n\n\n\n<li>\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u6027\u3068\u53ef\u8aad\u6027\u306e\u5411\u4e0a<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-2\">\u30af\u30e9\u30b9\u3068\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u95a2\u4fc2\u6027\u3092\u56f3\u89e3\u3067\u7406\u89e3<\/h3>\n\n\n\n<p>\u30af\u30e9\u30b9\u3068\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u95a2\u4fc2\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5177\u4f53\u4f8b\u3067\u7406\u89e3\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=\"\"># \u30af\u30e9\u30b9\u306e\u5b9a\u7fa9\nclass Car\n  def initialize(color)\n    @color = color  # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\n  end\n\n  def start_engine\n    puts \"\u30a8\u30f3\u30b8\u30f3\u3092\u59cb\u52d5\u3057\u307e\u3059\"\n  end\nend\n\n# \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u4f5c\u6210\nred_car = Car.new(\"red\")    # Car\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b91\nblue_car = Car.new(\"blue\")  # Car\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b92\n\n# \u305d\u308c\u305e\u308c\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u540c\u3058\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u7528\nred_car.start_engine   # =&gt; \u30a8\u30f3\u30b8\u30f3\u3092\u59cb\u52d5\u3057\u307e\u3059\nblue_car.start_engine  # =&gt; \u30a8\u30f3\u30b8\u30f3\u3092\u59cb\u52d5\u3057\u307e\u3059<\/pre>\n\n\n\n<p>\u3053\u306e\u30b3\u30fc\u30c9\u304b\u3089\u5206\u304b\u308b\u91cd\u8981\u306a\u30dd\u30a4\u30f3\u30c8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u30af\u30e9\u30b9\u306f\u8a2d\u8a08\u56f3<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>Car<\/code>\u30af\u30e9\u30b9\u306f\u30af\u30eb\u30de\u306e\u8a2d\u8a08\u56f3\u3068\u3057\u3066\u6a5f\u80fd<\/li>\n\n\n\n<li>\u5c5e\u6027\uff08\u8272\uff09\u3068\u30e1\u30bd\u30c3\u30c9\uff08\u30a8\u30f3\u30b8\u30f3\u59cb\u52d5\uff09\u3092\u5b9a\u7fa9<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f\u5b9f\u4f53<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>red_car<\/code>\u3068<code>blue_car<\/code>\u306f<code>Car<\/code>\u30af\u30e9\u30b9\u304b\u3089\u4f5c\u3089\u308c\u305f\u500b\u5225\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8<\/li>\n\n\n\n<li>\u305d\u308c\u305e\u308c\u304c\u72ec\u81ea\u306e\u72b6\u614b\uff08\u8272\uff09\u3092\u6301\u3064<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u30e1\u30bd\u30c3\u30c9\u306e\u5171\u6709<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u540c\u3058\u30af\u30e9\u30b9\u304b\u3089\u4f5c\u3089\u308c\u305f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f\u3001\u540c\u3058\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u7528\u53ef\u80fd<\/li>\n\n\n\n<li>\u5404\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u72ec\u7acb\u3057\u3066\u5b9f\u884c\u3055\u308c\u308b<\/li>\n<\/ul>\n\n\n\n<p>\u30af\u30e9\u30b9\u3068\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u95a2\u4fc2\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u7279\u5fb4\u304c\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n<div id=\"id-2e5eccef-2b08-4e4f-8aad-ebc381c4f4ef\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u9805\u76ee<\/th><th>\u30af\u30e9\u30b9<\/th><th>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9<\/th><\/tr><\/thead><tbody><tr><td>\u5f79\u5272<\/td><td>\u8a2d\u8a08\u56f3\u30fb\u578b\u306e\u5b9a\u7fa9<\/td><td>\u5177\u4f53\u7684\u306a\u30aa\u30d6\u30b8\u30a7\u30af\u30c8<\/td><\/tr><tr><td>\u500b\u6570<\/td><td>1\u3064<\/td><td>\u8907\u6570\u53ef\u80fd<\/td><\/tr><tr><td>\u30e1\u30e2\u30ea<\/td><td>\u30af\u30e9\u30b9\u5b9a\u7fa9\u306e\u307f<\/td><td>\u500b\u5225\u306b\u30e1\u30e2\u30ea\u3092\u6d88\u8cbb<\/td><\/tr><tr><td>\u72b6\u614b<\/td><td>\u30af\u30e9\u30b9\u5909\u6570\u306e\u307f<\/td><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u3067\u500b\u5225\u306e\u72b6\u614b\u3092\u6301\u3064<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u5b9f\u969b\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3067\u306f\u3001\u30af\u30e9\u30b9\u3092\u9069\u5207\u306b\u8a2d\u8a08\u3059\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u6574\u7406\u3055\u308c\u305f\u3001\u4fdd\u5b88\u6027\u306e\u9ad8\u3044\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u5177\u4f53\u7684\u306a\u30af\u30e9\u30b9\u306e\u4f5c\u308a\u65b9\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-3\">\u30af\u30e9\u30b9\u306e\u4f5c\u308a\u65b9\u3092\u30de\u30b9\u30bf\u30fc\u3057\u3088\u3046<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-4\">\u30af\u30e9\u30b9\u5b9a\u7fa9\u306e\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3068\u547d\u540d\u898f\u5247<\/h3>\n\n\n\n<p>Ruby\u3067\u306e\u30af\u30e9\u30b9\u5b9a\u7fa9\u306f\u3001\u30b7\u30f3\u30d7\u30eb\u3067\u3042\u308a\u306a\u304c\u3089\u5f37\u529b\u306a\u6a5f\u80fd\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3068\u3001Ruby\u30b3\u30df\u30e5\u30cb\u30c6\u30a3\u3067\u5e83\u304f\u63a1\u7528\u3055\u308c\u3066\u3044\u308b\u547d\u540d\u898f\u5247\u3092\u7d39\u4ecb\u3057\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=\"\"># \u30af\u30e9\u30b9\u540d\u306f\u5927\u6587\u5b57\u3067\u59cb\u307e\u308b\u30ad\u30e3\u30e1\u30eb\u30b1\u30fc\u30b9\nclass BankAccount\n  # \u30af\u30e9\u30b9\u5909\u6570\uff08\u5168\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u5171\u6709\uff09\n  @@total_accounts = 0\n\n  # \u5b9a\u6570\u306f\u5168\u3066\u5927\u6587\u5b57\n  MINIMUM_BALANCE = 1000\n\n  # \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\n  def initialize(account_number, balance)\n    # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u306f@\u3067\u59cb\u307e\u308b\n    @account_number = account_number\n    @balance = balance\n    @@total_accounts += 1\n  end\nend<\/pre>\n\n\n\n<p>\u547d\u540d\u898f\u5247\u306e\u30dd\u30a4\u30f3\u30c8\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30af\u30e9\u30b9\u540d\uff1aPascalCase\uff08\u4f8b\uff1a<code>BankAccount<\/code>, <code>UserProfile<\/code>\uff09<\/li>\n\n\n\n<li>\u30e1\u30bd\u30c3\u30c9\u540d\uff1asnake_case\uff08\u4f8b\uff1a<code>deposit_money<\/code>, <code>check_balance<\/code>\uff09<\/li>\n\n\n\n<li>\u5909\u6570\u540d\uff1asnake_case\uff08\u4f8b\uff1a<code>account_number<\/code>, <code>current_balance<\/code>\uff09<\/li>\n\n\n\n<li>\u5b9a\u6570\uff1aSCREAMING_SNAKE_CASE\uff08\u4f8b\uff1a<code>MINIMUM_BALANCE<\/code>, <code>MAX_ATTEMPTS<\/code>\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-5\">\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u3068\u30af\u30e9\u30b9\u5909\u6570\u306e\u4f7f\u3044\u65b9<\/h3>\n\n\n\n<p>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u3068\u30af\u30e9\u30b9\u5909\u6570\u306f\u3001\u7570\u306a\u308b\u7528\u9014\u3068\u7279\u5fb4\u3092\u6301\u3063\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=\"\">class Student\n  # \u30af\u30e9\u30b9\u5909\u6570\uff08\u5168\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3067\u5171\u6709\uff09\n  @@school_name = \"Ruby\u5b66\u5712\"\n  @@student_count = 0\n\n  # \u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u3067\u30af\u30e9\u30b9\u5909\u6570\u306b\u30a2\u30af\u30bb\u30b9\n  def self.school_info\n    \"\u5b66\u6821\u540d: #{@@school_name}, \u751f\u5f92\u6570: #{@@student_count}\u540d\"\n  end\n\n  def initialize(name, grade)\n    # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\uff08\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u56fa\u6709\uff09\n    @name = name\n    @grade = grade\n    @@student_count += 1\n  end\n\n  # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u3078\u306e\u30a2\u30af\u30bb\u30b5\u30e1\u30bd\u30c3\u30c9\n  def student_info\n    \"\u540d\u524d: #{@name}, \u5b66\u5e74: #{@grade}\u5e74\u751f\"\n  end\nend\n\n# \u4f7f\u7528\u4f8b\nstudent1 = Student.new(\"\u7530\u4e2d\", 2)\nstudent2 = Student.new(\"\u9234\u6728\", 1)\n\nputs Student.school_info  # =&gt; \"\u5b66\u6821\u540d: Ruby\u5b66\u5712, \u751f\u5f92\u6570: 2\u540d\"\nputs student1.student_info  # =&gt; \"\u540d\u524d: \u7530\u4e2d, \u5b66\u5e74: 2\u5e74\u751f\"<\/pre>\n\n\n\n<p>\u5909\u6570\u306e\u7279\u5fb4\u6bd4\u8f03\uff1a<\/p>\n\n\n<div id=\"id-c7db360f-4807-48ab-a358-039c074520b7\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7a2e\u985e<\/th><th>\u8a18\u6cd5<\/th><th>\u30b9\u30b3\u30fc\u30d7<\/th><th>\u5171\u6709\u7bc4\u56f2<\/th><th>\u4e3b\u306a\u7528\u9014<\/th><\/tr><\/thead><tbody><tr><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570<\/td><td>@\u5909\u6570\u540d<\/td><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5185<\/td><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3054\u3068<\/td><td>\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u72b6\u614b\u7ba1\u7406<\/td><\/tr><tr><td>\u30af\u30e9\u30b9\u5909\u6570<\/td><td>@@\u5909\u6570\u540d<\/td><td>\u30af\u30e9\u30b9\u5185<\/td><td>\u30af\u30e9\u30b9\u5168\u4f53<\/td><td>\u30af\u30e9\u30b9\u5168\u4f53\u3067\u306e\u60c5\u5831\u5171\u6709<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\" id=\"i-6\">\u30e1\u30bd\u30c3\u30c9\u5b9a\u7fa9\u3068\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\u306e\u91cd\u8981\u6027<\/h3>\n\n\n\n<p>\u30e1\u30bd\u30c3\u30c9\u306e\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306e\u91cd\u8981\u306a\u6982\u5ff5\u306e\u4e00\u3064\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=\"\">class CreditCard\n  # \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\n  def initialize(number, limit)\n    @number = number\n    @limit = limit\n    @charges = []\n  end\n\n  # public\u30e1\u30bd\u30c3\u30c9\uff08\u30c7\u30d5\u30a9\u30eb\u30c8\uff09\n  def charge(amount)\n    if valid_charge?(amount)\n      add_charge(amount)\n      \"\u652f\u6255\u3044\u5b8c\u4e86\uff1a#{amount}\u5186\"\n    else\n      \"\u9650\u5ea6\u984d\u8d85\u904e\"\n    end\n  end\n\n  # protected\u30e1\u30bd\u30c3\u30c9\n  protected\n  def transfer_limit(other_card)\n    @limit + other_card.limit\n  end\n\n  # private\u30e1\u30bd\u30c3\u30c9\n  private\n  def valid_charge?(amount)\n    total_charges + amount &lt;= @limit\n  end\n\n  def add_charge(amount)\n    @charges &lt;&lt; amount\n  end\n\n  def total_charges\n    @charges.sum\n  end\nend<\/pre>\n\n\n\n<p>\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\u306e\u7a2e\u985e\uff1a<\/p>\n\n\n<div id=\"id-cee9dba8-3bb1-429b-a338-842068691620\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u30a2\u30af\u30bb\u30b9\u30ec\u30d9\u30eb<\/th><th>\u547c\u3073\u51fa\u3057\u5236\u9650<\/th><th>\u4e3b\u306a\u7528\u9014<\/th><\/tr><\/thead><tbody><tr><td>public<\/td><td>\u5236\u9650\u306a\u3057<\/td><td>\u5916\u90e8\u304b\u3089\u306e\u64cd\u4f5c\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9<\/td><\/tr><tr><td>protected<\/td><td>\u540c\u3058\u30af\u30e9\u30b9\u3068\u30b5\u30d6\u30af\u30e9\u30b9\u5185<\/td><td>\u30af\u30e9\u30b9\u9593\u306e\u9023\u643a\u51e6\u7406<\/td><\/tr><tr><td>private<\/td><td>\u30af\u30e9\u30b9\u5185\u306e\u307f<\/td><td>\u5185\u90e8\u5b9f\u88c5\u306e\u8a73\u7d30\u51e6\u7406<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<p>\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\u3092\u9069\u5207\u306b\u8a2d\u5b9a\u3059\u308b\u3053\u3068\u3067\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30ab\u30d7\u30bb\u30eb\u5316\u306e\u5b9f\u73fe<\/li>\n\n\n\n<li>\u30b3\u30fc\u30c9\u306e\u4fdd\u5b88\u6027\u5411\u4e0a<\/li>\n\n\n\n<li>\u4e88\u671f\u305b\u306c\u30d0\u30b0\u306e\u9632\u6b62<\/li>\n\n\n\n<li>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u660e\u78ba\u5316<\/li>\n<\/ul>\n\n\n\n<p>\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u57fa\u672c\u3092\u62bc\u3055\u3048\u305f\u4e0a\u3067\u3001\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3088\u308a\u5b9f\u8df5\u7684\u306a\u30c6\u30af\u30cb\u30c3\u30af\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-7\">\u30af\u30e9\u30b9\u3092\u4f7f\u3044\u3053\u306a\u3059\u305f\u3081\u306e7\u3064\u306e\u5b9f\u8df5\u30c6\u30af\u30cb\u30c3\u30af<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-8\">\u7d99\u627f\u3092\u6d3b\u7528\u3057\u305f\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u65b9\u6cd5<\/h3>\n\n\n\n<p>\u7d99\u627f\u306f\u3001\u65e2\u5b58\u306e\u30af\u30e9\u30b9\u306e\u6a5f\u80fd\u3092\u53d7\u3051\u7d99\u304e\u306a\u304c\u3089\u3001\u65b0\u3057\u3044\u6a5f\u80fd\u3092\u8ffd\u52a0\u3067\u304d\u308b\u5f37\u529b\u306a\u6a5f\u80fd\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=\"\"># \u57fa\u5e95\u30af\u30e9\u30b9\nclass Animal\n  def initialize(name)\n    @name = name\n  end\n\n  def speak\n    raise NotImplementedError, \"\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u5b9f\u88c5\u3057\u3066\u304f\u3060\u3055\u3044\"\n  end\n\n  def introduce\n    \"\u79c1\u306e\u540d\u524d\u306f#{@name}\u3067\u3059\u3002#{speak}\"\n  end\nend\n\n# \u7d99\u627f\u3092\u4f7f\u7528\u3057\u305f\u6d3e\u751f\u30af\u30e9\u30b9\nclass Dog &lt; Animal\n  def speak\n    \"\u30ef\u30f3\u30ef\u30f3\uff01\"\n  end\nend\n\nclass Cat &lt; Animal\n  def speak\n    \"\u30cb\u30e3\u30fc\uff01\"\n  end\nend\n\n# \u4f7f\u7528\u4f8b\ndog = Dog.new(\"\u30dd\u30c1\")\ncat = Cat.new(\"\u30bf\u30de\")\n\nputs dog.introduce  # =&gt; \"\u79c1\u306e\u540d\u524d\u306f\u30dd\u30c1\u3067\u3059\u3002\u30ef\u30f3\u30ef\u30f3\uff01\"\nputs cat.introduce  # =&gt; \"\u79c1\u306e\u540d\u524d\u306f\u30bf\u30de\u3067\u3059\u3002\u30cb\u30e3\u30fc\uff01\"<\/pre>\n\n\n\n<p>\u7d99\u627f\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5171\u901a\u306e\u632f\u308b\u821e\u3044\u306f\u57fa\u5e95\u30af\u30e9\u30b9\u306b\u5b9a\u7fa9<\/li>\n\n\n\n<li>\u30b5\u30d6\u30af\u30e9\u30b9\u56fa\u6709\u306e\u51e6\u7406\u306f\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3067\u5b9f\u88c5<\/li>\n\n\n\n<li>\u7d99\u627f\u306e\u6df1\u3055\u306f\u6d45\u304f\u4fdd\u3064\uff083\u968e\u5c64\u307e\u3067\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-9\">\u30e2\u30b8\u30e5\u30fc\u30eb\u3067\u30af\u30e9\u30b9\u306b\u6a5f\u80fd\u3092\u8ffd\u52a0\u3059\u308b<\/h3>\n\n\n\n<p>\u30e2\u30b8\u30e5\u30fc\u30eb\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u8907\u6570\u306e\u30af\u30e9\u30b9\u3067\u6a5f\u80fd\u3092\u5171\u6709\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=\"\"># \u5171\u901a\u6a5f\u80fd\u3092\u30e2\u30b8\u30e5\u30fc\u30eb\u3068\u3057\u3066\u5b9a\u7fa9\nmodule Loggable\n  def log(message)\n    puts \"[#{Time.now}] #{message}\"\n  end\nend\n\n# \u30e2\u30b8\u30e5\u30fc\u30eb\u3092\u30af\u30e9\u30b9\u306b\u7d44\u307f\u8fbc\u3080\nclass UserAccount\n  include Loggable\n\n  def deposit(amount)\n    log(\"#{amount}\u5186\u304c\u9810\u3051\u5165\u308c\u3089\u308c\u307e\u3057\u305f\")\n    # \u9810\u91d1\u51e6\u7406\n  end\nend\n\nclass AdminAccount\n  include Loggable\n\n  def system_check\n    log(\"\u30b7\u30b9\u30c6\u30e0\u30c1\u30a7\u30c3\u30af\u3092\u5b9f\u884c\u3057\u307e\u3057\u305f\")\n    # \u30c1\u30a7\u30c3\u30af\u51e6\u7406\n  end\nend\n\n# \u4f7f\u7528\u4f8b\nuser = UserAccount.new\nuser.deposit(1000)  # =&gt; [2024-12-03 10:30:15] 1000\u5186\u304c\u9810\u3051\u5165\u308c\u3089\u308c\u307e\u3057\u305f<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-10\">\u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u3067\u5171\u901a\u51e6\u7406\u3092\u5b9f\u88c5\u3059\u308b<\/h3>\n\n\n\n<p>\u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u306f\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u6210\u305b\u305a\u306b\u4f7f\u7528\u3067\u304d\u308b\u4fbf\u5229\u306a\u6a5f\u80fd\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=\"\">class DateFormatter\n  # \u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u306e\u5b9a\u7fa9\uff08\u65b9\u6cd51\uff09\n  def self.to_jp(date)\n    date.strftime(\"%Y\u5e74%m\u6708%d\u65e5\")\n  end\n\n  # \u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u306e\u5b9a\u7fa9\uff08\u65b9\u6cd52\uff09\n  class &lt;&lt; self\n    def to_short(date)\n      date.strftime(\"%m\/%d\")\n    end\n\n    def to_long(date)\n      date.strftime(\"%Y\u5e74%m\u6708%d\u65e5 %H\u6642%M\u5206\")\n    end\n  end\nend\n\n# \u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u7528\u4f8b\ntoday = Time.now\nputs DateFormatter.to_jp(today)    # =&gt; \"2024\u5e7412\u670803\u65e5\"\nputs DateFormatter.to_short(today) # =&gt; \"12\/03\"<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-11\">initialize\u30e1\u30bd\u30c3\u30c9\u3067\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u521d\u671f\u5316\u3059\u308b<\/h3>\n\n\n\n<p><code>initialize<\/code>\u30e1\u30bd\u30c3\u30c9\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u521d\u671f\u72b6\u614b\u3092\u8a2d\u5b9a\u3059\u308b\u91cd\u8981\u306a\u5f79\u5272\u3092\u679c\u305f\u3057\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=\"\">class Employee\n  def initialize(id, name, department = \"\u672a\u6240\u5c5e\")\n    # \u5fc5\u9808\u30d1\u30e9\u30e1\u30fc\u30bf\n    @id = id\n    @name = name\n    # \u30aa\u30d7\u30b7\u30e7\u30ca\u30eb\u30d1\u30e9\u30e1\u30fc\u30bf\n    @department = department\n    # \u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u306e\u8a2d\u5b9a\n    @hire_date = Time.now\n    @active = true\n\n    # \u521d\u671f\u5316\u6642\u306e\u691c\u8a3c\n    validate_id(id)\n    setup_employee\n  end\n\n  private\n\n  def validate_id(id)\n    raise ArgumentError, \"ID\u306f\u6b63\u306e\u6574\u6570\u3067\u3042\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\" unless id.is_a?(Integer) &amp;&amp; id &gt; 0\n  end\n\n  def setup_employee\n    # \u5f93\u696d\u54e1\u306e\u521d\u671f\u8a2d\u5b9a\u51e6\u7406\n  end\nend<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-12\">attr_accessor\u3067\u308f\u304b\u308a\u3084\u3059\u3044\u30b3\u30fc\u30c9\u3092\u66f8\u304f<\/h3>\n\n\n\n<p><code>attr_accessor<\/code>\u3068\u305d\u306e\u4ef2\u9593\u305f\u3061\u3092\u4f7f\u3063\u3066\u3001\u7c21\u6f54\u3067\u8aad\u307f\u3084\u3059\u3044\u30b3\u30fc\u30c9\u3092\u66f8\u3051\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=\"\">class Product\n  # \u8aad\u307f\u66f8\u304d\u4e21\u65b9\u53ef\u80fd\n  attr_accessor :name, :price\n\n  # \u8aad\u307f\u53d6\u308a\u306e\u307f\u53ef\u80fd\n  attr_reader :id, :created_at\n\n  # \u66f8\u304d\u8fbc\u307f\u306e\u307f\u53ef\u80fd\n  attr_writer :secret_code\n\n  def initialize(id, name, price)\n    @id = id\n    @name = name\n    @price = price\n    @created_at = Time.now\n  end\n\n  # \u30ab\u30b9\u30bf\u30e0\u306e\u30b2\u30c3\u30bf\u30fc\n  def price_with_tax\n    (@price * 1.1).round\n  end\nend\n\n# \u4f7f\u7528\u4f8b\nproduct = Product.new(1, \"Ruby\u672c\", 2000)\nproduct.name = \"\u6539\u8a02\u7248Ruby\u672c\"  # attr_accessor\u3067\u5b9a\u7fa9\u3057\u305f\u30bb\u30c3\u30bf\u30fc\nputs product.name             # attr_accessor\u3067\u5b9a\u7fa9\u3057\u305f\u30b2\u30c3\u30bf\u30fc\nputs product.price_with_tax   # \u30ab\u30b9\u30bf\u30e0\u30b2\u30c3\u30bf\u30fc<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-13\">private\u30e1\u30bd\u30c3\u30c9\u3067\u30ab\u30d7\u30bb\u30eb\u5316\u3092\u5b9f\u73fe\u3059\u308b<\/h3>\n\n\n\n<p>private\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u30af\u30e9\u30b9\u306e\u5185\u90e8\u5b9f\u88c5\u3092\u96a0\u853d\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=\"\">class PaymentProcessor\n  def process_payment(amount)\n    if validate_amount(amount)\n      deduct_payment(amount)\n      send_confirmation\n      true\n    else\n      false\n    end\n  end\n\n  private\n\n  def validate_amount(amount)\n    amount.is_a?(Numeric) &amp;&amp; amount &gt; 0\n  end\n\n  def deduct_payment(amount)\n    # \u652f\u6255\u3044\u51e6\u7406\u306e\u5b9f\u88c5\n  end\n\n  def send_confirmation\n    # \u78ba\u8a8d\u30e1\u30fc\u30eb\u9001\u4fe1\u306e\u5b9f\u88c5\n  end\nend\n\n# \u4f7f\u7528\u4f8b\nprocessor = PaymentProcessor.new\nprocessor.process_payment(1000)  # OK\n# processor.validate_amount(1000) # \u30a8\u30e9\u30fc\uff1aprivate\u30e1\u30bd\u30c3\u30c9\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u306a\u3044<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-14\">\u30af\u30e9\u30b9\u5b9a\u6570\u3092\u52b9\u679c\u7684\u306b\u4f7f\u7528\u3059\u308b<\/h3>\n\n\n\n<p>\u30af\u30e9\u30b9\u5b9a\u6570\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u8a2d\u5b9a\u5024\u3084\u56fa\u5b9a\u5024\u3092\u5206\u304b\u308a\u3084\u3059\u304f\u7ba1\u7406\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=\"\">class ShoppingCart\n  # \u5b9a\u6570\u306e\u5b9a\u7fa9\n  TAX_RATE = 0.1\n  FREE_SHIPPING_THRESHOLD = 5000\n  MAX_ITEMS = 20\n\n  def initialize\n    @items = []\n  end\n\n  def add_item(item)\n    if @items.size &lt; MAX_ITEMS\n      @items &lt;&lt; item\n    else\n      raise \"\u30ab\u30fc\u30c8\u306e\u6700\u5927\u6570#{MAX_ITEMS}\u3092\u8d85\u3048\u3066\u3044\u307e\u3059\"\n    end\n  end\n\n  def total\n    subtotal = @items.sum(&amp;:price)\n    tax = subtotal * TAX_RATE\n    shipping = subtotal &gt;= FREE_SHIPPING_THRESHOLD ? 0 : calculate_shipping\n\n    subtotal + tax + shipping\n  end\nend<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u30c6\u30af\u30cb\u30c3\u30af\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u6027\u304c\u9ad8\u304f\u3001\u518d\u5229\u7528\u53ef\u80fd\u306a\u30af\u30e9\u30b9\u3092\u8a2d\u8a08\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u30af\u30e9\u30b9\u8a2d\u8a08\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\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-15\">\u8a2d\u8a08\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-16\">\u5358\u4e00\u8cac\u4efb\u306e\u539f\u5247\u306b\u57fa\u3065\u304f\u30af\u30e9\u30b9\u8a2d\u8a08<\/h3>\n\n\n\n<p>\u5358\u4e00\u8cac\u4efb\u306e\u539f\u5247\uff08Single Responsibility Principle\uff09\u306f\u3001\u4e00\u3064\u306e\u30af\u30e9\u30b9\u306f\u4e00\u3064\u306e\u8cac\u4efb\u306e\u307f\u3092\u6301\u3064\u3079\u304d\u3068\u3044\u3046\u8003\u3048\u65b9\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=\"\"># \u60aa\u3044\u4f8b\uff1a\u8907\u6570\u306e\u8cac\u4efb\u304c\u6df7\u5728\nclass Order\n  def initialize(items)\n    @items = items\n  end\n\n  def calculate_total\n    # \u6ce8\u6587\u91d1\u984d\u306e\u8a08\u7b97\n  end\n\n  def save_to_database\n    # \u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3078\u306e\u4fdd\u5b58\n  end\n\n  def send_confirmation_email\n    # \u30e1\u30fc\u30eb\u9001\u4fe1\n  end\nend\n\n# \u826f\u3044\u4f8b\uff1a\u8cac\u4efb\u3092\u9069\u5207\u306b\u5206\u5272\nclass Order\n  def initialize(items)\n    @items = items\n  end\n\n  def calculate_total\n    @items.sum { |item| item.price * item.quantity }\n  end\nend\n\nclass OrderRepository\n  def save(order)\n    # \u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3078\u306e\u4fdd\u5b58\u30ed\u30b8\u30c3\u30af\n  end\nend\n\nclass OrderNotifier\n  def send_confirmation(order)\n    # \u30e1\u30fc\u30eb\u9001\u4fe1\u30ed\u30b8\u30c3\u30af\n  end\nend<\/pre>\n\n\n\n<p>\u5358\u4e00\u8cac\u4efb\u306e\u539f\u5247\u306e\u30e1\u30ea\u30c3\u30c8\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30b3\u30fc\u30c9\u306e\u4fdd\u5b88\u6027\u304c\u5411\u4e0a<\/li>\n\n\n\n<li>\u30c6\u30b9\u30c8\u304c\u66f8\u304d\u3084\u3059\u304f\u306a\u308b<\/li>\n\n\n\n<li>\u5909\u66f4\u306e\u5f71\u97ff\u7bc4\u56f2\u304c\u9650\u5b9a\u3055\u308c\u308b<\/li>\n\n\n\n<li>\u518d\u5229\u7528\u6027\u304c\u9ad8\u307e\u308b<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-17\">\u6b63\u3057\u3044\u30af\u30e9\u30b9\u540d\u3067\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u6027\u3092\u9ad8\u3081\u308b<\/h3>\n\n\n\n<p>\u30af\u30e9\u30b9\u540d\u306f\u3001\u305d\u306e\u30af\u30e9\u30b9\u306e\u5f79\u5272\u3068\u8cac\u4efb\u3092\u9069\u5207\u306b\u8868\u73fe\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\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=\"\"># \u60aa\u3044\u4f8b\uff1a\u62bd\u8c61\u7684\u3067\u5f79\u5272\u304c\u4e0d\u660e\u78ba\nclass Manager\n  # \u69d8\u3005\u306a\u7ba1\u7406\u6a5f\u80fd\u304c\u6df7\u5728\nend\n\n# \u826f\u3044\u4f8b\uff1a\u5177\u4f53\u7684\u3067\u5f79\u5272\u304c\u660e\u78ba\nclass UserAuthenticationManager\n  def authenticate(username, password)\n    # \u8a8d\u8a3c\u30ed\u30b8\u30c3\u30af\n  end\n\n  def generate_token(user)\n    # \u30c8\u30fc\u30af\u30f3\u751f\u6210\u30ed\u30b8\u30c3\u30af\n  end\nend\n\nclass OrderProcessManager\n  def process(order)\n    # \u6ce8\u6587\u51e6\u7406\u30ed\u30b8\u30c3\u30af\n  end\n\n  def cancel(order)\n    # \u30ad\u30e3\u30f3\u30bb\u30eb\u51e6\u7406\u30ed\u30b8\u30c3\u30af\n  end\nend<\/pre>\n\n\n\n<p>\u547d\u540d\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\uff1a<\/p>\n\n\n<div id=\"id-40097447-aecc-4573-bde3-84f799ac97f0\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u30d1\u30bf\u30fc\u30f3<\/th><th>\u4f8b<\/th><th>\u7528\u9014<\/th><\/tr><\/thead><tbody><tr><td>\u540d\u8a5e<\/td><td><code>User<\/code>, <code>Product<\/code><\/td><td>\u30a8\u30f3\u30c6\u30a3\u30c6\u30a3\u3092\u8868\u3059\u30af\u30e9\u30b9<\/td><\/tr><tr><td>\u5f62\u5bb9\u8a5e + \u540d\u8a5e<\/td><td><code>ActiveUser<\/code>, <code>PendingOrder<\/code><\/td><td>\u72b6\u614b\u3092\u6301\u3064\u30af\u30e9\u30b9<\/td><\/tr><tr><td>\u52d5\u8a5e + \u540d\u8a5e<\/td><td><code>PaymentProcessor<\/code>, <code>OrderValidator<\/code><\/td><td>\u30b5\u30fc\u30d3\u30b9\u30af\u30e9\u30b9<\/td><\/tr><tr><td>Manager\/Service<\/td><td><code>UserManager<\/code>, <code>PaymentService<\/code><\/td><td>\u8907\u96d1\u306a\u64cd\u4f5c\u3092\u7ba1\u7406\u3059\u308b\u30af\u30e9\u30b9<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\" id=\"i-18\">\u30c6\u30b9\u30c8\u3057\u3084\u3059\u3044\u30af\u30e9\u30b9\u306e\u4f5c\u308a\u65b9<\/h3>\n\n\n\n<p>\u30c6\u30b9\u30bf\u30d3\u30ea\u30c6\u30a3\u306e\u9ad8\u3044\u30af\u30e9\u30b9\u3092\u8a2d\u8a08\u3059\u308b\u3053\u3068\u3067\u3001\u54c1\u8cea\u306e\u9ad8\u3044\u30b3\u30fc\u30c9\u3092\u7dad\u6301\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=\"\"># \u30c6\u30b9\u30c8\u3057\u306b\u304f\u3044\u8a2d\u8a08\nclass WeatherReport\n  def initialize\n    @api = WeatherAPI.new  # \u76f4\u63a5\u4f9d\u5b58\n  end\n\n  def today_forecast\n    data = @api.fetch_weather\n    \"\u4eca\u65e5\u306e\u5929\u6c17: #{data['weather']}, \u6c17\u6e29: #{data['temperature']}\u5ea6\"\n  end\nend\n\n# \u30c6\u30b9\u30c8\u3057\u3084\u3059\u3044\u8a2d\u8a08\nclass WeatherReport\n  def initialize(weather_api)\n    @api = weather_api  # \u4f9d\u5b58\u6027\u306e\u6ce8\u5165\n  end\n\n  def today_forecast\n    data = @api.fetch_weather\n    format_forecast(data)\n  end\n\n  private\n\n  def format_forecast(data)\n    \"\u4eca\u65e5\u306e\u5929\u6c17: #{data['weather']}, \u6c17\u6e29: #{data['temperature']}\u5ea6\"\n  end\nend\n\n# \u30c6\u30b9\u30c8\u30b3\u30fc\u30c9\u4f8b\nclass WeatherAPIStub\n  def fetch_weather\n    { 'weather' =&gt; '\u6674\u308c', 'temperature' =&gt; 25 }\n  end\nend\n\n# \u30c6\u30b9\u30c8\u304c\u5bb9\u6613\nreport = WeatherReport.new(WeatherAPIStub.new)\nputs report.today_forecast<\/pre>\n\n\n\n<p>\u30c6\u30b9\u30bf\u30d6\u30eb\u306a\u8a2d\u8a08\u306e\u30dd\u30a4\u30f3\u30c8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u4f9d\u5b58\u6027\u306e\u6ce8\u5165\u3092\u6d3b\u7528\u3059\u308b<\/li>\n\n\n\n<li>\u526f\u4f5c\u7528\u3092\u9650\u5b9a\u7684\u306b\u3059\u308b<\/li>\n\n\n\n<li>\u30e1\u30bd\u30c3\u30c9\u3092\u5c0f\u3055\u304f\u4fdd\u3064<\/li>\n\n\n\n<li>\u30d1\u30d6\u30ea\u30c3\u30af\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u660e\u78ba\u306b\u3059\u308b<\/li>\n\n\n\n<li>\u30c6\u30b9\u30c8\u30c7\u30fc\u30bf\u306e\u6e96\u5099\u3092\u5bb9\u6613\u306b\u3059\u308b<\/li>\n<\/ol>\n\n\n\n<p>\u3053\u306e\u3088\u3046\u306a\u8a2d\u8a08\u539f\u5247\u3092\u610f\u8b58\u3059\u308b\u3053\u3068\u3067\u3001\u9577\u671f\u7684\u306a\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u6027\u3068\u62e1\u5f35\u6027\u3092\u78ba\u4fdd\u3067\u304d\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u89e3\u6c7a\u65b9\u6cd5\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-19\">\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u89e3\u6c7a\u65b9\u6cd5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-20\">NameError\u306e\u539f\u56e0\u3068\u5bfe\u51e6\u6cd5<\/h3>\n\n\n\n<p>NameError\u306f\u3001\u672a\u5b9a\u7fa9\u306e\u5909\u6570\u3084\u30e1\u30bd\u30c3\u30c9\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3088\u3046\u3068\u3057\u305f\u969b\u306b\u767a\u751f\u3059\u308b\u4e00\u822c\u7684\u306a\u30a8\u30e9\u30fc\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=\"\"># \u3088\u304f\u3042\u308bNameError\u306e\u4f8b\u3068\u89e3\u6c7a\u65b9\u6cd5\nclass User\n  def initialize(name)\n    @name = name\n  end\n\n  def greet\n    # \u30a8\u30e9\u30fc\u4f8b1: \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u306e\u30bf\u30a4\u30d7\u30df\u30b9\n    puts \"\u3053\u3093\u306b\u3061\u306f\u3001#{@nmae}\u3055\u3093\"  # @name\u306e\u30bf\u30a4\u30d7\u30df\u30b9\n\n    # \u6b63\u3057\u3044\u5b9f\u88c5\n    puts \"\u3053\u3093\u306b\u3061\u306f\u3001#{@name}\u3055\u3093\"\n  end\n\n  def self.find_by_name(name)\n    # \u30a8\u30e9\u30fc\u4f8b2: \u672a\u5b9a\u7fa9\u306e\u5b9a\u6570\n    DATABASE.find(name)  # DATABASE\u304c\u672a\u5b9a\u7fa9\n\n    # \u6b63\u3057\u3044\u5b9f\u88c5\n    @@database.find(name)  # \u30af\u30e9\u30b9\u5909\u6570\u3092\u4f7f\u7528\n  end\nend<\/pre>\n\n\n\n<p>\u4e00\u822c\u7684\u306aNameError\u306e\u5bfe\u51e6\u6cd5\uff1a<\/p>\n\n\n<div id=\"id-05d1bf0d-8a26-4e1d-9e86-d28c47028b69\">\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u30a8\u30e9\u30fc\u30d1\u30bf\u30fc\u30f3<\/th><th>\u539f\u56e0<\/th><th>\u89e3\u6c7a\u65b9\u6cd5<\/th><\/tr><\/thead><tbody><tr><td>\u5909\u6570\u540d\u306e\u30bf\u30a4\u30d7\u30df\u30b9<\/td><td>\u30b9\u30da\u30eb\u30df\u30b9\u3084\u5927\u5c0f\u6587\u5b57\u306e\u9593\u9055\u3044<\/td><td>\u5909\u6570\u540d\u3092\u6b63\u78ba\u306b\u8a18\u8ff0\u3059\u308b<\/td><\/tr><tr><td>\u672a\u5b9a\u7fa9\u306e\u5b9a\u6570<\/td><td>\u5b9a\u6570\u304c\u5b9a\u7fa9\u3055\u308c\u308b\u524d\u306b\u30a2\u30af\u30bb\u30b9<\/td><td>\u5b9a\u6570\u3092\u9069\u5207\u306b\u5b9a\u7fa9\u3059\u308b<\/td><\/tr><tr><td>\u30b9\u30b3\u30fc\u30d7\u306e\u554f\u984c<\/td><td>\u5909\u6570\u306e\u30b9\u30b3\u30fc\u30d7\u5916\u304b\u3089\u306e\u30a2\u30af\u30bb\u30b9<\/td><td>\u9069\u5207\u306a\u30b9\u30b3\u30fc\u30d7\u3067\u5909\u6570\u3092\u5b9a\u7fa9\u3059\u308b<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\" id=\"i-21\">NoMethodError\u3092\u89e3\u6c7a\u3059\u308b\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n\n\n\n<p>NoMethodError\u306f\u3001\u5b58\u5728\u3057\u306a\u3044\u30e1\u30bd\u30c3\u30c9\u3092\u547c\u3073\u51fa\u305d\u3046\u3068\u3057\u305f\u969b\u306b\u767a\u751f\u3057\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=\"\">class Product\n  attr_reader :name, :price\n\n  def initialize(name, price)\n    @name = name\n    @price = price\n  end\n\n  # \u30a8\u30e9\u30fc\u4f8b1: undefined method 'name='\n  def update_info(new_name)\n    name = new_name  # \u3053\u308c\u306f\u65b0\u3057\u3044\u30ed\u30fc\u30ab\u30eb\u5909\u6570\u3092\u4f5c\u6210\u3057\u3066\u3057\u307e\u3046\n  end\n\n  # \u6b63\u3057\u3044\u5b9f\u88c5\n  def update_info(new_name)\n    @name = new_name  # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u3092\u76f4\u63a5\u66f4\u65b0\n  end\n\n  # \u30a8\u30e9\u30fc\u4f8b2: protected\/private\u30e1\u30bd\u30c3\u30c9\u306e\u547c\u3073\u51fa\u3057\n  def self.total_price(products)\n    products.sum(&amp;:calculate_tax)  # private\u30e1\u30bd\u30c3\u30c9\u3092\u5916\u90e8\u304b\u3089\u547c\u3073\u51fa\u305d\u3046\u3068\u3057\u3066\u3044\u308b\n  end\n\n  private\n\n  def calculate_tax\n    @price * 1.1\n  end\nend<\/pre>\n\n\n\n<p>NoMethodError\u3078\u306e\u5bfe\u51e6\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30e1\u30bd\u30c3\u30c9\u540d\u306e\u30b9\u30da\u30eb\u30c1\u30a7\u30c3\u30af<\/li>\n\n\n\n<li>\u30a2\u30af\u30bb\u30b9\u5236\u5fa1\uff08public\/protected\/private\uff09\u306e\u78ba\u8a8d<\/li>\n\n\n\n<li>\u7d99\u627f\u95a2\u4fc2\u306e\u898b\u76f4\u3057<\/li>\n\n\n\n<li><code>respond_to?<\/code>\u306b\u3088\u308b\u4e8b\u524d\u30c1\u30a7\u30c3\u30af\u306e\u5b9f\u88c5<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-22\">\u30b9\u30b3\u30fc\u30d7\u95a2\u9023\u306e\u30c8\u30e9\u30d6\u30eb\u30b7\u30e5\u30fc\u30c6\u30a3\u30f3\u30b0<\/h3>\n\n\n\n<p>\u30b9\u30b3\u30fc\u30d7\u306e\u7406\u89e3\u4e0d\u8db3\u306b\u3088\u308b\u30a8\u30e9\u30fc\u306f\u983b\u7e41\u306b\u767a\u751f\u3057\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=\"\">class Account\n  @@account_count = 0  # \u30af\u30e9\u30b9\u5909\u6570\n\n  def initialize\n    @balance = 0      # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\n    total = 0         # \u30ed\u30fc\u30ab\u30eb\u5909\u6570\n    @@account_count += 1\n  end\n\n  def deposit(amount)\n    balance = @balance + amount  # \u65b0\u3057\u3044\u30ed\u30fc\u30ab\u30eb\u5909\u6570\u3092\u4f5c\u6210\u3057\u3066\u3057\u307e\u3046\n    # @balance = @balance + amount  # \u6b63\u3057\u3044\u5b9f\u88c5\n\n    # \u30b9\u30b3\u30fc\u30d7\u306e\u554f\u984c\u4f8b\n    puts total  # \u30a8\u30e9\u30fc\uff1atotal\u306finitialize\u5185\u306e\u30ed\u30fc\u30ab\u30eb\u5909\u6570\n\n    # \u6b63\u3057\u3044\u30a2\u30af\u30bb\u30b9\u65b9\u6cd5\n    puts @balance  # \u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u306f\u4ed6\u306e\u30e1\u30bd\u30c3\u30c9\u304b\u3089\u30a2\u30af\u30bb\u30b9\u53ef\u80fd\n    puts @@account_count  # \u30af\u30e9\u30b9\u5909\u6570\u3082\u540c\u69d8\n  end\n\n  def self.total_accounts\n    puts @@account_count  # \u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u304b\u3089\u30af\u30e9\u30b9\u5909\u6570\u306b\u30a2\u30af\u30bb\u30b9\u53ef\u80fd\n    puts @balance        # \u30a8\u30e9\u30fc\uff1a\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\u306f\u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u304b\u3089\u30a2\u30af\u30bb\u30b9\u4e0d\u53ef\n  end\nend<\/pre>\n\n\n\n<p>\u30b9\u30b3\u30fc\u30d7\u95a2\u9023\u306e\u554f\u984c\u3092\u9632\u3050\u305f\u3081\u306e\u30c1\u30a7\u30c3\u30af\u30ea\u30b9\u30c8\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u5909\u6570\uff08@\uff09\u3068\u30ed\u30fc\u30ab\u30eb\u5909\u6570\u306e\u533a\u5225<\/li>\n\n\n\n<li>\u30af\u30e9\u30b9\u5909\u6570\uff08@@\uff09\u306e\u9069\u5207\u306a\u4f7f\u7528<\/li>\n\n\n\n<li>\u30e1\u30bd\u30c3\u30c9\u5185\u3067\u306e\u30ed\u30fc\u30ab\u30eb\u5909\u6570\u306e\u521d\u671f\u5316<\/li>\n\n\n\n<li>\u30af\u30e9\u30b9\u30e1\u30bd\u30c3\u30c9\u3068\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u30e1\u30bd\u30c3\u30c9\u3067\u306e\u30b9\u30b3\u30fc\u30d7\u306e\u9055\u3044\u306e\u7406\u89e3<\/li>\n<\/ul>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u30a8\u30e9\u30fc\u30d1\u30bf\u30fc\u30f3\u3092\u7406\u89e3\u3057\u3001\u9069\u5207\u306a\u5bfe\u51e6\u6cd5\u3092\u77e5\u3063\u3066\u304a\u304f\u3053\u3068\u3067\u3001\u30c7\u30d0\u30c3\u30b0\u4f5c\u696d\u3092\u52b9\u7387\u5316\u3067\u304d\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u5b9f\u8df5\u7684\u306a\u30b3\u30fc\u30c9\u4f8b\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"i-23\">\u5b9f\u8df5\u7684\u306a\u30b3\u30fc\u30c9\u4f8b\u3067\u5b66\u3076\u30af\u30e9\u30b9\u306e\u6d3b\u7528<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-24\">\u30e6\u30fc\u30b6\u30fc\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u306e\u5b9f\u88c5\u4f8b<\/h3>\n\n\n\n<p>\u5b9f\u7528\u7684\u306a\u30e6\u30fc\u30b6\u30fc\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u306e\u4f8b\u3092\u901a\u3058\u3066\u3001\u30af\u30e9\u30b9\u8a2d\u8a08\u306e\u5b9f\u8df5\u7684\u306a\u30a2\u30d7\u30ed\u30fc\u30c1\u3092\u898b\u3066\u3044\u304d\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=\"\">require 'bcrypt'\nrequire 'securerandom'\n\nclass User\n  attr_reader :id, :email, :created_at\n  attr_accessor :name\n\n  def initialize(email:, name:)\n    @id = SecureRandom.uuid\n    @email = email\n    @name = name\n    @created_at = Time.now\n    @active = true\n  end\n\n  def self.authenticate(email, password)\n    user = find_by_email(email)\n    return nil unless user\n    user.valid_password?(password) ? user : nil\n  end\n\n  private\n\n  def valid_password?(password)\n    BCrypt::Password.new(@password_hash) == password\n  end\n\n  def password=(new_password)\n    @password_hash = BCrypt::Password.create(new_password)\n  end\nend\n\nclass UserManager\n  def initialize\n    @users = {}\n  end\n\n  def register(email:, name:, password:)\n    return false if email_exists?(email)\n\n    user = User.new(email: email, name: name)\n    user.send(:password=, password)\n    @users[user.id] = user\n\n    notify_registration(user)\n    true\n  end\n\n  private\n\n  def email_exists?(email)\n    @users.values.any? { |user| user.email == email }\n  end\n\n  def notify_registration(user)\n    # \u30e1\u30fc\u30eb\u9001\u4fe1\u306a\u3069\u306e\u51e6\u7406\n    puts \"Welcome #{user.name}! Registration completed.\"\n  end\nend\n\n# \u4f7f\u7528\u4f8b\nmanager = UserManager.new\nmanager.register(\n  email: \"user@example.com\",\n  name: \"\u5c71\u7530\u592a\u90ce\",\n  password: \"secure_password123\"\n)<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-25\">\u5728\u5eab\u7ba1\u7406\u30af\u30e9\u30b9\u306e\u4f5c\u6210\u624b\u9806<\/h3>\n\n\n\n<p>\u5728\u5eab\u7ba1\u7406\u30b7\u30b9\u30c6\u30e0\u306e\u5b9f\u88c5\u3092\u901a\u3058\u3066\u3001\u3088\u308a\u8907\u96d1\u306a\u30af\u30e9\u30b9\u8a2d\u8a08\u3092\u5b66\u3073\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=\"\">module Inventory\n  class Product\n    attr_reader :id, :name, :price, :stock_count\n\n    def initialize(id:, name:, price:, initial_stock: 0)\n      @id = id\n      @name = name\n      @price = price\n      @stock_count = initial_stock\n      @reorder_point = 10\n      @reorder_quantity = 50\n    end\n\n    def add_stock(quantity)\n      @stock_count += quantity\n    end\n\n    def remove_stock(quantity)\n      raise InsufficientStockError if quantity &gt; @stock_count\n      @stock_count -= quantity\n    end\n\n    def needs_reorder?\n      @stock_count &lt;= @reorder_point\n    end\n  end\n\n  class StockManager\n    def initialize\n      @products = {}\n      @stock_history = []\n    end\n\n    def register_product(product)\n      @products[product.id] = product\n    end\n\n    def process_order(order)\n      order.items.each do |item|\n        product = @products[item.product_id]\n        product.remove_stock(item.quantity)\n        record_transaction(:out, product, item.quantity)\n      end\n    end\n\n    def receive_shipment(shipment)\n      shipment.items.each do |item|\n        product = @products[item.product_id]\n        product.add_stock(item.quantity)\n        record_transaction(:in, product, item.quantity)\n      end\n    end\n\n    private\n\n    def record_transaction(type, product, quantity)\n      @stock_history &lt;&lt; {\n        timestamp: Time.now,\n        type: type,\n        product_id: product.id,\n        quantity: quantity\n      }\n    end\n  end\nend\n\n# \u4f7f\u7528\u4f8b\nproduct = Inventory::Product.new(\n  id: 1,\n  name: \"\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u5165\u9580\u66f8\",\n  price: 2800,\n  initial_stock: 100\n)\n\nmanager = Inventory::StockManager.new\nmanager.register_product(product)<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"i-26\">\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3067\u5b66\u3076\u30c7\u30b6\u30a4\u30f3\u30d1\u30bf\u30fc\u30f3<\/h3>\n\n\n\n<p>Ruby\u3067\u3088\u304f\u4f7f\u7528\u3055\u308c\u308b\u30c7\u30b6\u30a4\u30f3\u30d1\u30bf\u30fc\u30f3\u306e\u5b9f\u88c5\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=\"\"># Observer\u30d1\u30bf\u30fc\u30f3\nmodule Observable\n  def add_observer(observer)\n    @observers ||= []\n    @observers &lt;&lt; observer\n  end\n\n  def notify_observers(*args)\n    @observers&amp;.each { |observer| observer.update(*args) }\n  end\nend\n\nclass StockItem\n  include Observable\n\n  attr_reader :name, :quantity\n\n  def initialize(name, quantity)\n    @name = name\n    @quantity = quantity\n  end\n\n  def update_quantity(new_quantity)\n    old_quantity = @quantity\n    @quantity = new_quantity\n    notify_observers(self, old_quantity, new_quantity)\n  end\nend\n\nclass StockMonitor\n  def update(item, old_quantity, new_quantity)\n    if new_quantity &lt; old_quantity\n      puts \"\u5728\u5eab\u6e1b\u5c11\u8b66\u544a: #{item.name}\u306e\u5728\u5eab\u304c#{old_quantity}\u304b\u3089#{new_quantity}\u306b\u6e1b\u5c11\u3057\u307e\u3057\u305f\"\n    elsif new_quantity == 0\n      puts \"\u5728\u5eab\u5207\u308c\u8b66\u544a: #{item.name}\u306e\u5728\u5eab\u304c\u306a\u304f\u306a\u308a\u307e\u3057\u305f\"\n    end\n  end\nend\n\n# Singleton\u30d1\u30bf\u30fc\u30f3\nrequire 'singleton'\n\nclass Logger\n  include Singleton\n\n  def initialize\n    @logs = []\n  end\n\n  def log(message)\n    @logs &lt;&lt; {\n      timestamp: Time.now,\n      message: message\n    }\n  end\n\n  def display_logs\n    @logs.each do |log|\n      puts \"[#{log[:timestamp]}] #{log[:message]}\"\n    end\n  end\nend\n\n# \u4f7f\u7528\u4f8b\n# Observer\u30d1\u30bf\u30fc\u30f3\nitem = StockItem.new(\"Ruby\u672c\", 10)\nmonitor = StockMonitor.new\nitem.add_observer(monitor)\nitem.update_quantity(5)  # \u5728\u5eab\u6e1b\u5c11\u8b66\u544a\u304c\u8868\u793a\u3055\u308c\u308b\nitem.update_quantity(0)  # \u5728\u5eab\u5207\u308c\u8b66\u544a\u304c\u8868\u793a\u3055\u308c\u308b\n\n# Singleton\u30d1\u30bf\u30fc\u30f3\nlogger = Logger.instance\nlogger.log(\"\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u8d77\u52d5\")\nlogger.log(\"\u30e6\u30fc\u30b6\u30fc\u30ed\u30b0\u30a4\u30f3: user123\")\nlogger.display_logs<\/pre>\n\n\n\n<p>\u3053\u308c\u3089\u306e\u5b9f\u8df5\u7684\u306a\u4f8b\u3092\u901a\u3058\u3066\u3001\u30af\u30e9\u30b9\u3092\u4f7f\u7528\u3057\u305f\u52b9\u679c\u7684\u306a\u30b3\u30fc\u30c9\u8a2d\u8a08\u3068\u5b9f\u88c5\u65b9\u6cd5\u3092\u5b66\u3076\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u5b9f\u969b\u306e\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u3082\u3001\u3053\u308c\u3089\u306e\u30d1\u30bf\u30fc\u30f3\u3084\u30c6\u30af\u30cb\u30c3\u30af\u3092\u6d3b\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u4fdd\u5b88\u6027\u304c\u9ad8\u304f\u3001\u62e1\u5f35\u6027\u306e\u3042\u308b\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Warning: Undefined array key &#8220;is_admin&#8221; in \/home\/xs392991\/dexall.co.jp\/public_html\/articles\/wp-content\/themes\/ &#8230; <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":{"0":"post-1256","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-ruby","7":"nothumb"},"_links":{"self":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1256","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1256"}],"version-history":[{"count":1,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1256\/revisions"}],"predecessor-version":[{"id":1257,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=\/wp\/v2\/posts\/1256\/revisions\/1257"}],"wp:attachment":[{"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1256"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1256"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dexall.co.jp\/articles\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1256"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}