{"id":225,"date":"2024-10-02T15:01:05","date_gmt":"2024-10-02T06:01:05","guid":{"rendered":"https:\/\/dexall.co.jp\/articles\/?p=225"},"modified":"2025-03-24T08:54:57","modified_gmt":"2025-03-23T23:54:57","slug":"java-extends%e3%83%9e%e3%82%b9%e3%82%bf%e3%83%bc%e8%ac%9b%e5%ba%a7%ef%bc%9a%e7%b6%99%e6%89%bf%e3%81%ae%e5%9f%ba%e7%a4%8e%e3%81%8b%e3%82%89%e5%bf%9c%e7%94%a8%e3%81%be%e3%81%a7%e5%ae%8c%e5%85%a8","status":"publish","type":"post","link":"https:\/\/dexall.co.jp\/articles\/?p=225","title":{"rendered":"Java extends\u30de\u30b9\u30bf\u30fc\u8b1b\u5ea7\uff1a\u7d99\u627f\u306e\u57fa\u790e\u304b\u3089\u5fdc\u7528\u307e\u3067\u5b8c\u5168\u89e3\u8aac\u30102024\u5e74\u6700\u65b0\u7248\u3011"},"content":{"rendered":"<div id=\"sgb-css-id-1\">\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\">1. Java extends\u3068\u306f\uff1f\u7d99\u627f\u306e\u57fa\u672c\u6982\u5ff5\u3092\u7406\u89e3\u3057\u3088\u3046<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-1\">1.1. extends\u30ad\u30fc\u30ef\u30fc\u30c9\u306e\u5f79\u5272\u3068\u4f7f\u3044\u65b9<\/a>      <\/li>      <li>        <a href=\"#i-2\">1.2. \u89aa\u30af\u30e9\u30b9\u3068\u5b50\u30af\u30e9\u30b9\u306e\u95a2\u4fc2\u6027<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-3\">1.3. \u7d99\u627f\u306e\u30e1\u30ea\u30c3\u30c8\uff1a\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u3068\u62e1\u5f35\u6027<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-4\">2. Java extends\u306e\u5b9f\u8df5\uff1a\u5177\u4f53\u7684\u306a\u4f7f\u7528\u4f8b\u3067\u5b66\u3076<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-5\">2.1. \u30b7\u30f3\u30d7\u30eb\u306a\u7d99\u627f\u306e\u4f8b\uff1a\u52d5\u7269\u30af\u30e9\u30b9\u3068\u72ac\u30af\u30e9\u30b9<\/a>      <\/li>      <li>        <a href=\"#i-6\">2.2. \u30e1\u30bd\u30c3\u30c9\u306e\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\uff1a\u89aa\u30af\u30e9\u30b9\u306e\u632f\u308b\u821e\u3044\u3092\u5909\u66f4\u3059\u308b<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-7\">2.3. super()\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4f7f\u3063\u305f\u89aa\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u547c\u3073\u51fa\u3057<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-8\">3. Java extends\u306e\u5fdc\u7528\uff1a\u7d99\u627f\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-9\">3.1. \u7d99\u627f\u306e\u968e\u5c64\u3092\u6d45\u304f\u4fdd\u3064\u7406\u7531\u3068\u65b9\u6cd5<\/a>      <\/li>      <li>        <a href=\"#i-10\">3.2. \u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3vs\u7d99\u627f\uff1a\u9069\u5207\u306a\u4f7f\u3044\u5206\u3051<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-11\">3.3. final\u4fee\u98fe\u5b50\u3092\u4f7f\u3063\u3066\u7d99\u627f\u3092\u5236\u9650\u3059\u308b\u5834\u5408<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-12\">4. Java extends\u3068\u4ed6\u306eOOP\u6982\u5ff5\u3068\u306e\u95a2\u4fc2\u6027<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-13\">4.1. \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3068\u306e\u9055\u3044\uff1aimplements\u3068extends\u306e\u4f7f\u3044\u5206\u3051<\/a>      <\/li>      <li>        <a href=\"#i-14\">4.2. \u62bd\u8c61\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3059\u308b\uff1a\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\u30d1\u30bf\u30fc\u30f3<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-15\">4.3. \u591a\u91cd\u7d99\u627f\u306e\u5236\u9650\u3068\u305d\u306e\u56de\u907f\u7b56<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-16\">5. \u5b9f\u52d9\u3067\u306eJava extends\u6d3b\u7528\u8853<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-17\">5.1. \u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3084\u30e9\u30a4\u30d6\u30e9\u30ea\u306e\u62e1\u5f35\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>      <li>        <a href=\"#i-18\">5.2. \u30c6\u30b9\u30c8\u99c6\u52d5\u958b\u767a\uff08TDD\uff09\u306b\u304a\u3051\u308b\u7d99\u627f\u306e\u5229\u7528<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-19\">5.3. \u30ec\u30ac\u30b7\u30fc\u30b3\u30fc\u30c9\u306e\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u3068\u7d99\u627f\u306e\u518d\u8a2d\u8a08<\/a>      <\/li>    <\/ul>  <\/li>  <li>    <a href=\"#i-20\">6. Java extends\u306e\u843d\u3068\u3057\u7a74\u3068\u5bfe\u7b56<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-21\">6.1. \u7d99\u627f\u306e\u4e71\u7528\u304c\u3082\u305f\u3089\u3059\u554f\u984c\u70b9<\/a>      <\/li>      <li>        <a href=\"#i-22\">6.2. \u8106\u5f31\u306a\u57fa\u5e95\u30af\u30e9\u30b9\u554f\u984c\u3068\u305d\u306e\u89e3\u6c7a\u7b56<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-23\">6.3. \u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3078\u306e\u5f71\u97ff\u3068\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/a>      <\/li>    <\/ul>  <\/li>  <li class=\"last\">    <a href=\"#i-24\">7. Java 17\u4ee5\u964d\u306eextends\u306b\u95a2\u3059\u308b\u65b0\u6a5f\u80fd\u3068\u5c06\u6765\u5c55\u671b<\/a>    <ul class=\"menu_level_1\">      <li class=\"first\">        <a href=\"#i-25\">7.1. \u30b7\u30fc\u30eb\u30c9\u30af\u30e9\u30b9\u3068\u7d99\u627f\u306e\u5236\u5fa1<\/a>      <\/li>      <li>        <a href=\"#i-26\">7.2. \u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u3068\u7d99\u627f\u968e\u5c64\u306e\u6271\u3044<\/a>      <\/li>      <li class=\"last\">        <a href=\"#i-27\">7.3. \u4eca\u5f8c\u306eJava\u8a00\u8a9e\u4ed5\u69d8\u306b\u304a\u3051\u308b\u7d99\u627f\u306e\u4f4d\u7f6e\u3065\u3051<\/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\">1. Java extends\u3068\u306f\uff1f\u7d99\u627f\u306e\u57fa\u672c\u6982\u5ff5\u3092\u7406\u89e3\u3057\u3088\u3046<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-2\">\n<p>Java\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306b\u304a\u3044\u3066\u3001<code>extends<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u306f\u975e\u5e38\u306b\u91cd\u8981\u306a\u5f79\u5272\u3092\u679c\u305f\u3057\u307e\u3059\u3002\u3053\u306e\u30ad\u30fc\u30ef\u30fc\u30c9\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\uff08OOP\uff09\u306e\u6838\u5fc3\u7684\u306a\u6982\u5ff5\u3067\u3042\u308b\u300c\u7d99\u627f\u300d\u3092\u5b9f\u73fe\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3055\u308c\u307e\u3059\u3002\u7d99\u627f\u3068\u306f\u3001\u65e2\u5b58\u306e\u30af\u30e9\u30b9\uff08\u89aa\u30af\u30e9\u30b9\uff09\u306e\u7279\u6027\u3092\u65b0\u3057\u3044\u30af\u30e9\u30b9\uff08\u5b50\u30af\u30e9\u30b9\uff09\u306b\u5f15\u304d\u7d99\u3050\u4ed5\u7d44\u307f\u306e\u3053\u3068\u3067\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-3\">\n<h3 class=\"wp-block-heading\" id=\"i-1\">1.1. extends\u30ad\u30fc\u30ef\u30fc\u30c9\u306e\u5f79\u5272\u3068\u4f7f\u3044\u65b9<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-4\">\n<p><code>extends<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u306f\u3001\u65b0\u3057\u3044\u30af\u30e9\u30b9\u3092\u5b9a\u7fa9\u3059\u308b\u969b\u306b\u3001\u65e2\u5b58\u306e\u30af\u30e9\u30b9\u3092\u62e1\u5f35\uff08\u7d99\u627f\uff09\u3059\u308b\u3053\u3068\u3092\u5ba3\u8a00\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3057\u307e\u3059\u3002\u57fa\u672c\u7684\u306a\u69cb\u6587\u306f\u4ee5\u4e0b\u306e\u3068\u304a\u308a\u3067\u3059\u3002<\/p>\n<\/div>\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 \u5b50\u30af\u30e9\u30b9\u540d extends \u89aa\u30af\u30e9\u30b9\u540d {\n    \/\/ \u5b50\u30af\u30e9\u30b9\u306e\u5185\u5bb9\n}<\/pre>\n\n\n<div id=\"sgb-css-id-5\">\n<p>\u3053\u306e\u69cb\u6587\u306b\u3088\u308a\u3001\u5b50\u30af\u30e9\u30b9\u306f\u89aa\u30af\u30e9\u30b9\u306e\u7279\u6027\uff08\u30d5\u30a3\u30fc\u30eb\u30c9\u3084\u30e1\u30bd\u30c3\u30c9\uff09\u3092\u81ea\u52d5\u7684\u306b\u7d99\u627f\u3057\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u304c\u9ad8\u307e\u308a\u3001\u968e\u5c64\u7684\u306a\u30af\u30e9\u30b9\u69cb\u9020\u3092\u4f5c\u6210\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-6\">\n<h3 class=\"wp-block-heading\" id=\"i-2\">1.2. \u89aa\u30af\u30e9\u30b9\u3068\u5b50\u30af\u30e9\u30b9\u306e\u95a2\u4fc2\u6027<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-7\">\n<p>\u7d99\u627f\u95a2\u4fc2\u306b\u3042\u308b\u89aa\u30af\u30e9\u30b9\u3068\u5b50\u30af\u30e9\u30b9\u306f\u3001\u300cis-a\u95a2\u4fc2\u300d\u3068\u547c\u3070\u308c\u308b\u95a2\u4fc2\u6027\u3092\u6301\u3061\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u300c\u5b50\u30af\u30e9\u30b9\u306f\u89aa\u30af\u30e9\u30b9\u306e\u4e00\u7a2e\u3067\u3042\u308b\u300d\u3068\u3044\u3046\u95a2\u4fc2\u3067\u3059\u3002\u4f8b\u3048\u3070\u3001\u300c\u72ac\u306f\u52d5\u7269\u306e\u4e00\u7a2e\u3067\u3042\u308b\u300d\u3068\u3044\u3046\u95a2\u4fc2\u3092\u8868\u73fe\u3059\u308b\u5834\u5408\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u30b3\u30fc\u30c9\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">public class Animal {\n    protected String name;\n\n    public void eat() {\n        System.out.println(name + \" is eating.\");\n    }\n}\n\npublic class Dog extends Animal {\n    public void bark() {\n        System.out.println(name + \" is barking.\");\n    }\n}\n<\/pre>\n\n\n<div id=\"sgb-css-id-8\">\n<p>\u3053\u306e\u4f8b\u3067\u306f\u3001<code>Dog<\/code>\u30af\u30e9\u30b9\u306f<code>Animal<\/code>\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u3066\u3044\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001<code data-enlighter-language=\"generic\" class=\"EnlighterJSRAW\">Dog<\/code>\u30af\u30e9\u30b9\u306f<code>Animal<\/code>\u30af\u30e9\u30b9\u306e<code>name<\/code>\u30d5\u30a3\u30fc\u30eb\u30c9\u3068<code>eat()<\/code>\u30e1\u30bd\u30c3\u30c9\u3092\u7d99\u627f\u3057\u3001\u3055\u3089\u306b\u72ec\u81ea\u306e<code>bark()<\/code>\u30e1\u30bd\u30c3\u30c9\u3092\u8ffd\u52a0\u3057\u3066\u3044\u307e\u3059\u3002 \u5b50\u30af\u30e9\u30b9\u306f\u89aa\u30af\u30e9\u30b9\u306e<code>public<\/code>\u3068<code>protected<\/code>\u30e1\u30f3\u30d0\u30fc\uff08\u30d5\u30a3\u30fc\u30eb\u30c9\u3084\u30e1\u30bd\u30c3\u30c9\uff09\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u5b50\u30af\u30e9\u30b9\u306f\u89aa\u30af\u30e9\u30b9\u306e\u6a5f\u80fd\u3092\u5229\u7528\u3057\u3064\u3064\u3001\u65b0\u3057\u3044\u6a5f\u80fd\u3092\u8ffd\u52a0\u3057\u305f\u308a\u65e2\u5b58\u306e\u6a5f\u80fd\u3092\u5909\u66f4\u3057\u305f\u308a\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-9\">\n<h3 class=\"wp-block-heading\" id=\"i-3\">1.3. \u7d99\u627f\u306e\u30e1\u30ea\u30c3\u30c8\uff1a\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u3068\u62e1\u5f35\u6027<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-10\">\n<p>\u7d99\u627f\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u91cd\u8981\u306a\u30e1\u30ea\u30c3\u30c8\u304c\u5f97\u3089\u308c\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u306e\u91cd\u8981\u306a\u30e1\u30ea\u30c3\u30c8<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-11\">\n<li><strong>\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u5411\u4e0a<\/strong>\uff1a\u89aa\u30af\u30e9\u30b9\u306b\u5b9a\u7fa9\u3055\u308c\u305f\u6a5f\u80fd\u3092\u5b50\u30af\u30e9\u30b9\u3067\u518d\u5229\u7528\u3067\u304d\u308b\u305f\u3081\u3001\u30b3\u30fc\u30c9\u306e\u91cd\u8907\u3092\u6e1b\u3089\u305b\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-12\">\n<li><strong>\u62e1\u5f35\u6027\u306e\u78ba\u4fdd<\/strong>\uff1a\u65e2\u5b58\u306e\u30af\u30e9\u30b9\u3092\u62e1\u5f35\u3057\u3066\u65b0\u3057\u3044\u6a5f\u80fd\u3092\u8ffd\u52a0\u3067\u304d\u308b\u305f\u3081\u3001\u67d4\u8edf\u306a\u30d7\u30ed\u30b0\u30e9\u30e0\u8a2d\u8a08\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-13\">\n<li><strong>\u4fdd\u5b88\u6027\u306e\u5411\u4e0a<\/strong>\uff1a\u5171\u901a\u306e\u6a5f\u80fd\u3092\u89aa\u30af\u30e9\u30b9\u306b\u307e\u3068\u3081\u308b\u3053\u3068\u3067\u3001\u30b3\u30fc\u30c9\u306e\u7ba1\u7406\u304c\u5bb9\u6613\u306b\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-14\">\n<li><strong>\u591a\u614b\u6027\u306e\u5b9f\u73fe<\/strong>\uff1a\u89aa\u30af\u30e9\u30b9\u306e\u578b\u3067\u5b50\u30af\u30e9\u30b9\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u6271\u3048\u308b\u305f\u3081\u3001\u67d4\u8edf\u306a\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div><\/ul>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-15\">\n<p>\u7d99\u627f\u3092\u9069\u5207\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u30b3\u30fc\u30c9\u306e\u69cb\u9020\u5316\u3068\u518d\u5229\u7528\u6027\u304c\u5411\u4e0a\u3057\u3001\u3088\u308a\u4fdd\u5b88\u6027\u306e\u9ad8\u3044\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4f5c\u6210\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002 \u305f\u3060\u3057\u3001\u7d99\u627f\u306b\u306f\u6ce8\u610f\u70b9\u3082\u3042\u308a\u307e\u3059\u3002Java\u306f\u5358\u4e00\u7d99\u627f\u306e\u307f\u3092\u30b5\u30dd\u30fc\u30c8\u3057\u3066\u3044\u308b\u305f\u3081\u3001\u4e00\u3064\u306e\u30af\u30e9\u30b9\u304c\u8907\u6570\u306e\u30af\u30e9\u30b9\u3092\u76f4\u63a5\u7d99\u627f\u3059\u308b\u3053\u3068\u306f\u3067\u304d\u307e\u305b\u3093\u3002\u307e\u305f\u3001\u7d99\u627f\u306e\u968e\u5c64\u304c\u6df1\u304f\u306a\u308a\u3059\u304e\u308b\u3068\u3001\u30b3\u30fc\u30c9\u306e\u7406\u89e3\u3084\u4fdd\u5b88\u304c\u96e3\u3057\u304f\u306a\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u7d99\u627f\u306f\u614e\u91cd\u306b\u8a2d\u8a08\u3057\u3001\u9069\u5207\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002 <\/p>\n<\/div>\n\n<div id=\"sgb-css-id-16\">\n<p>\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3053\u308c\u3089\u306e\u6982\u5ff5\u3092\u3088\u308a\u5177\u4f53\u7684\u306a\u4f8b\u3092\u901a\u3058\u3066\u8a73\u3057\u304f\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-17\">\n<h2 class=\"wp-block-heading\" id=\"i-4\">2. Java extends\u306e\u5b9f\u8df5\uff1a\u5177\u4f53\u7684\u306a\u4f7f\u7528\u4f8b\u3067\u5b66\u3076<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-18\">\n<p>\u7d99\u627f\u306e\u6982\u5ff5\u3092\u7406\u89e3\u3057\u305f\u3068\u3053\u308d\u3067\u3001\u5b9f\u969b\u306e\u30b3\u30fc\u30c9\u4f8b\u3092\u901a\u3058\u3066Java\u306e<code>extends<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u306e\u4f7f\u3044\u65b9\u3092\u8a73\u3057\u304f\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002\u3053\u3053\u3067\u306f\u3001\u52d5\u7269\u30af\u30e9\u30b9\u3068\u72ac\u30af\u30e9\u30b9\u306e\u4f8b\u3092\u767a\u5c55\u3055\u305b\u3001\u7d99\u627f\u306e\u3055\u307e\u3056\u307e\u306a\u5074\u9762\u3092\u63a2\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-19\">\n<h3 class=\"wp-block-heading\" id=\"i-5\">2.1. \u30b7\u30f3\u30d7\u30eb\u306a\u7d99\u627f\u306e\u4f8b\uff1a\u52d5\u7269\u30af\u30e9\u30b9\u3068\u72ac\u30af\u30e9\u30b9<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-20\">\n<p>\u307e\u305a\u3001\u57fa\u672c\u7684\u306a\u7d99\u627f\u306e\u4f8b\u3068\u3057\u3066\u3001<code>Animal<\/code>\u30af\u30e9\u30b9\u3068<code>Dog<\/code>\u30af\u30e9\u30b9\u3092\u5b9a\u7fa9\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<\/div>\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=\"\">public class Animal {\n    protected String name;\n    protected int age;\n\n    public Animal(String name, int age) {\n        this.name = name;\n        this.age = age;\n    }\n\n    public void makeSound() {\n        System.out.println(\"The animal makes a sound\");\n    }\n}\n\npublic class Dog extends Animal {\n    private String breed;\n\n    public Dog(String name, int age, String breed) {\n        super(name, age);\n        this.breed = breed;\n    }\n\n    @Override\n    public void makeSound() {\n        System.out.println(name + \" barks: Woof! Woof!\");\n    }\n\n    public void fetch() {\n        System.out.println(name + \" is fetching the ball\");\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-21\">\n<p>\u3053\u306e\u4f8b\u3067\u306f\u3001<code>Dog<\/code>\u30af\u30e9\u30b9\u304c<code>Animal<\/code>\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u3066\u3044\u307e\u3059\u3002<code>Dog<\/code>\u30af\u30e9\u30b9\u306f<code>Animal<\/code>\u30af\u30e9\u30b9\u306e<code>name<\/code>\u3068<code>age<\/code>\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u7d99\u627f\u3057\u3001\u72ec\u81ea\u306e<code>breed<\/code>\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u8ffd\u52a0\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-22\">\n<h3 class=\"wp-block-heading\" id=\"i-6\">2.2. \u30e1\u30bd\u30c3\u30c9\u306e\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\uff1a\u89aa\u30af\u30e9\u30b9\u306e\u632f\u308b\u821e\u3044\u3092\u5909\u66f4\u3059\u308b<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-23\">\n<p>\u30e1\u30bd\u30c3\u30c9\u306e\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u306f\u3001\u5b50\u30af\u30e9\u30b9\u3067\u89aa\u30af\u30e9\u30b9\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u518d\u5b9a\u7fa9\u3059\u308b\u3053\u3068\u3067\u3059\u3002\u4e0a\u8a18\u306e\u4f8b\u3067\u306f\u3001<code>Dog<\/code>\u30af\u30e9\u30b9\u304c<code>Animal<\/code>\u30af\u30e9\u30b9\u306e<code>makeSound()<\/code>\u30e1\u30bd\u30c3\u30c9\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-24\">\n<p>\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3059\u308b\u969b\u306f\u3001\u4ee5\u4e0b\u306e\u70b9\u306b\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u306e\u6ce8\u610f\u70b9<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-25\">\n<li>\u30e1\u30bd\u30c3\u30c9\u540d\u3001\u623b\u308a\u5024\u306e\u578b\u3001\u5f15\u6570\u306e\u6570\u3068\u578b\u304c\u89aa\u30af\u30e9\u30b9\u3068\u540c\u3058\u3067\u3042\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-26\">\n<li>\u30a2\u30af\u30bb\u30b9\u4fee\u98fe\u5b50\u306f\u540c\u3058\u304b\u3001\u3088\u308a\u7de9\u3044\u5236\u9650\u306b\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-27\">\n<li><code>@Override<\/code>\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u3092\u4f7f\u7528\u3059\u308b\u3068\u3001\u30b3\u30f3\u30d1\u30a4\u30e9\u304c\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u306e\u6b63\u5f53\u6027\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3066\u304f\u308c\u307e\u3059\u3002<\/li>\n<\/div><\/ul>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-28\">\n<h3 class=\"wp-block-heading\" id=\"i-7\">2.3. super()\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4f7f\u3063\u305f\u89aa\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u547c\u3073\u51fa\u3057<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-29\">\n<p><code>super()<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u306f\u3001\u89aa\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u547c\u3073\u51fa\u3059\u305f\u3081\u306b\u4f7f\u7528\u3057\u307e\u3059\u3002<code>Dog<\/code>\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067<code>super(name, age);<\/code>\u3068\u8a18\u8ff0\u3059\u308b\u3053\u3068\u3067\u3001<code>Animal<\/code>\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u547c\u3073\u51fa\u3057\u3001<code>name<\/code>\u3068<code>age<\/code>\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u521d\u671f\u5316\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-30\">\n<p><code>super()<\/code>\u306e\u4f7f\u7528\u306b\u306f\u4ee5\u4e0b\u306e\u7279\u5fb4\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\"><code>super()<\/code>\u306e\u4f7f\u7528\u306b\u304a\u3051\u308b\u7279\u5fb4<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-31\">\n<li>\u5b50\u30af\u30e9\u30b9\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306e\u6700\u521d\u306e\u884c\u3067\u4f7f\u7528\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-32\">\n<li>\u660e\u793a\u7684\u306b\u547c\u3073\u51fa\u3055\u306a\u3044\u5834\u5408\u3001\u30c7\u30d5\u30a9\u30eb\u30c8\u3067\u89aa\u30af\u30e9\u30b9\u306e\u5f15\u6570\u306a\u3057\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u304c\u547c\u3073\u51fa\u3055\u308c\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-33\">\n<li>\u89aa\u30af\u30e9\u30b9\u306b\u5f15\u6570\u306a\u3057\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u304c\u306a\u3044\u5834\u5408\u306f\u3001\u660e\u793a\u7684\u306b<code>super()<\/code>\u3092\u547c\u3073\u51fa\u3059\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/li>\n<\/div><\/ul>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-34\">\n<p>\u5b9f\u52d9\u3067\u6d3b\u7528\u3059\u308b\u969b\u306e\u30d2\u30f3\u30c8\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u5b9f\u52d9\u3067\u6d3b\u7528\u3059\u308b\u969b\u306e\u30d2\u30f3\u30c8<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-35\">\n<li>\u5171\u901a\u306e\u5c5e\u6027\u3084\u632f\u308b\u821e\u3044\u3092\u6301\u3064\u30af\u30e9\u30b9\u7fa4\u3092\u8a2d\u8a08\u3059\u308b\u969b\u306b\u7d99\u627f\u3092\u4f7f\u7528\u3057\u307e\u3057\u3087\u3046\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-36\">\n<li>\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3084\u30e9\u30a4\u30d6\u30e9\u30ea\u306e\u30af\u30e9\u30b9\u3092\u62e1\u5f35\u3057\u3066\u3001\u30ab\u30b9\u30bf\u30e0\u6a5f\u80fd\u3092\u8ffd\u52a0\u3059\u308b\u969b\u306b\u7d99\u627f\u304c\u5f79\u7acb\u3061\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-37\">\n<li>\u30c6\u30b9\u30c8\u7528\u306e\u30e2\u30c3\u30af\u30af\u30e9\u30b9\u3092\u4f5c\u6210\u3059\u308b\u969b\u306b\u3001\u672c\u7269\u306e\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u3066\u4e00\u90e8\u306e\u632f\u308b\u821e\u3044\u3092\u5909\u66f4\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-38\">\n<p>\u3053\u308c\u3089\u306e\u4f8b\u3092\u901a\u3058\u3066\u3001Java\u306e\u7d99\u627f\u304c\u3044\u304b\u306b\u5f37\u529b\u3067\u67d4\u8edf\u306a\u30e1\u30ab\u30cb\u30ba\u30e0\u3067\u3042\u308b\u304b\u304c\u308f\u304b\u308a\u307e\u3059\u3002\u6b21\u306e\u30bb\u30af\u30b7\u30e7\u30f3\u3067\u306f\u3001\u3088\u308a\u9ad8\u5ea6\u306a\u7d99\u627f\u306e\u30c6\u30af\u30cb\u30c3\u30af\u3068\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u306b\u3064\u3044\u3066\u63a2\u3063\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-39\">\n<h2 class=\"wp-block-heading\" id=\"i-8\">3. Java extends\u306e\u5fdc\u7528\uff1a\u7d99\u627f\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-40\">\n<p>\u7d99\u627f\u306f\u5f37\u529b\u306a\u6a5f\u80fd\u3067\u3059\u304c\u3001\u9069\u5207\u306b\u4f7f\u7528\u3057\u306a\u3044\u3068\u8907\u96d1\u3067\u4fdd\u5b88\u304c\u96e3\u3057\u3044\u30b3\u30fc\u30c9\u306b\u306a\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001Java\u306e\u7d99\u627f\u3092\u52b9\u679c\u7684\u306b\u6d3b\u7528\u3059\u308b\u305f\u3081\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-41\">\n<h3 class=\"wp-block-heading\" id=\"i-9\">3.1. \u7d99\u627f\u306e\u968e\u5c64\u3092\u6d45\u304f\u4fdd\u3064\u7406\u7531\u3068\u65b9\u6cd5<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-42\">\n<p>\u7d99\u627f\u306e\u968e\u5c64\u3092\u6d45\u304f\u4fdd\u3064\u3053\u3068\u306f\u3001\u30b3\u30fc\u30c9\u306e\u8907\u96d1\u6027\u3092\u6e1b\u3089\u3057\u3001\u4fdd\u5b88\u6027\u3092\u5411\u4e0a\u3055\u305b\u3001\u30c7\u30d0\u30c3\u30b0\u3092\u5bb9\u6613\u306b\u3059\u308b\u305f\u3081\u306b\u91cd\u8981\u3067\u3059\u3002\u4ee5\u4e0b\u306e\u65b9\u6cd5\u3067\u968e\u5c64\u3092\u6d45\u304f\u4fdd\u3064\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u306e\u968e\u5c64\u3092\u6d45\u304f\u4fdd\u3064\u65b9\u6cd5<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-43\">\n<li>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u4f7f\u7528\uff1a\u5171\u901a\u306e\u632f\u308b\u821e\u3044\u3092\u5b9a\u7fa9\u3057\u3001\u8907\u6570\u306e\u30af\u30e9\u30b9\u3067\u5b9f\u88c5\u3059\u308b\u3053\u3068\u3067\u3001\u6df1\u3044\u7d99\u627f\u968e\u5c64\u3092\u907f\u3051\u3089\u308c\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-44\">\n<li>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u306e\u6d3b\u7528\uff1a\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4ed6\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u4e00\u90e8\u3068\u3057\u3066\u7d44\u307f\u8fbc\u3080\u3053\u3068\u3067\u3001\u67d4\u8edf\u306a\u8a2d\u8a08\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-45\">\n<li>\u7d99\u627f\u306e\u5fc5\u8981\u6027\u3092\u614e\u91cd\u306b\u8a55\u4fa1\uff1a\u672c\u5f53\u306b\u300cis-a\u300d\u95a2\u4fc2\u304c\u6210\u308a\u7acb\u3064\u304b\u3092\u78ba\u8a8d\u3057\u3001\u5fc5\u8981\u306a\u5834\u5408\u306e\u307f\u7d99\u627f\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/li>\n<\/div><\/ol>\n<\/div><\/div>\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=\"\">\/\/ \u6df1\u3044\u7d99\u627f\u968e\u5c64\u3092\u907f\u3051\u308b\u4f8b\ninterface Vehicle {\n    void move();\n}\n\nclass Car implements Vehicle {\n    @Override\n    public void move() {\n        System.out.println(\"Car is moving on the road\");\n    }\n}\n\nclass Bicycle implements Vehicle {\n    @Override\n    public void move() {\n        System.out.println(\"Bicycle is pedaling\");\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-46\">\n<h3 class=\"wp-block-heading\" id=\"i-10\">3.2. \u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3vs\u7d99\u627f\uff1a\u9069\u5207\u306a\u4f7f\u3044\u5206\u3051<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-47\">\n<p>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u3068\u7d99\u627f\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u8a2d\u8a08\u306e\u91cd\u8981\u306a\u6982\u5ff5\u3067\u3059\u3002\u9069\u5207\u306b\u4f7f\u3044\u5206\u3051\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u67d4\u8edf\u3067\u4fdd\u5b88\u6027\u306e\u9ad8\u3044\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f \u3068 \u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list\"><div id=\"sgb-css-id-48\">\n<li>\u7d99\u627f\uff1a\u300cis-a\u300d\u95a2\u4fc2\u304c\u6210\u308a\u7acb\u3064\u5834\u5408\u306b\u4f7f\u7528\u3057\u307e\u3059\uff08\u4f8b\uff1a\u72ac\u306f\u52d5\u7269\u3067\u3042\u308b\uff09\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-49\">\n<li>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\uff1a\u300chas-a\u300d\u95a2\u4fc2\u304c\u6210\u308a\u7acb\u3064\u5834\u5408\u306b\u4f7f\u7528\u3057\u307e\u3059\uff08\u4f8b\uff1a\u8eca\u306f\u30a8\u30f3\u30b8\u30f3\u3092\u6301\u3064\uff09\u3002<\/li>\n<\/div><\/ul>\n<\/div><\/div>\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=\"\">\/\/ \u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u306e\u4f8b\nclass Engine {\n    void start() {\n        System.out.println(\"Engine started\");\n    }\n}\n\nclass Car {\n    private Engine engine; \/\/ \u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\n\n    public Car() {\n        this.engine = new Engine();\n    }\n\n    void start() {\n        engine.start();\n        System.out.println(\"Car is ready to go\");\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-50\">\n<p>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u306f\u7d99\u627f\u3088\u308a\u3082\u67d4\u8edf\u6027\u304c\u9ad8\u304f\u3001\u7d50\u5408\u5ea6\u304c\u4f4e\u3044\u305f\u3081\u3001\u591a\u304f\u306e\u5834\u5408\u3067\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u3092\u512a\u5148\u3059\u308b\u3053\u3068\u304c\u63a8\u5968\u3055\u308c\u3066\u3044\u307e\u3059\uff08\u300c\u7d99\u627f\u3088\u308a\u5408\u6210\u300d\u306e\u539f\u5247\uff09\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-51\">\n<h3 class=\"wp-block-heading\" id=\"i-11\">3.3. final\u4fee\u98fe\u5b50\u3092\u4f7f\u3063\u3066\u7d99\u627f\u3092\u5236\u9650\u3059\u308b\u5834\u5408<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-52\">\n<p><code>final<\/code>\u4fee\u98fe\u5b50\u306f\u3001\u7d99\u627f\u3084\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3092\u5236\u9650\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3055\u308c\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u306e\u5236\u9650\u306b\u3064\u3044\u3066<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list\"><div id=\"sgb-css-id-53\">\n<li>\u30af\u30e9\u30b9\u306b<code>final<\/code>\u3092\u9069\u7528\uff1a\u305d\u306e\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3067\u304d\u306a\u304f\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-54\">\n<li>\u30e1\u30bd\u30c3\u30c9\u306b<code>final<\/code>\u3092\u9069\u7528\uff1a\u305d\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3067\u304d\u306a\u304f\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div><\/ul>\n<\/div><\/div>\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=\"\">final class ImmutableClass {\n    \/\/ \u3053\u306e\u4f8b\u306f\u7d99\u627f\u3067\u304d\u307e\u305b\u3093\n}\n\nclass BaseClass {\n    final void finalMethod() {\n        \/\/ \u3053\u306e\u30e1\u30bd\u30c3\u30c9\u306f\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3067\u304d\u307e\u305b\u3093\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-55\">\n<p><code>final<\/code>\u306e\u4f7f\u7528\u306b\u306f\u4ee5\u4e0b\u306e\u5229\u70b9\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-59\">\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\"><code>final<\/code> \u4f7f\u7528\u306e\u5229\u70b9<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list\"><div id=\"sgb-css-id-56\">\n<li>\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u306e\u5411\u4e0a<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-57\">\n<li>\u8a2d\u8a08\u306e\u610f\u56f3\u3092\u660e\u78ba\u306b\u3059\u308b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-58\">\n<li>\u5834\u5408\u306b\u3088\u3063\u3066\u306f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u6700\u9069\u5316\u306b\u3064\u306a\u304c\u308b<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n<\/div>\n\n<div id=\"sgb-css-id-60\">\n<p>\u305f\u3060\u3057\u3001<code>final<\/code>\u3092\u4f7f\u7528\u3059\u308b\u3068\u62e1\u5f35\u6027\u304c\u5236\u9650\u3055\u308c\u308b\u305f\u3081\u3001\u614e\u91cd\u306b\u4f7f\u7528\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-61\">\n<p>\u7d99\u627f\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u3092\u307e\u3068\u3081\u308b\u3068\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-67\">\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u4f7f\u7528\u306e\u7559\u610f\u4e8b\u9805<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list\"><div id=\"sgb-css-id-62\">\n<li>\u7d99\u627f\u3088\u308a\u3082\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u3092\u512a\u5148\u3059\u308b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-63\">\n<li>\u7d99\u627f\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u306f\u3001is-a\u95a2\u4fc2\u304c\u6210\u308a\u7acb\u3064\u3053\u3068\u3092\u78ba\u8a8d\u3059\u308b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-64\">\n<li>\u7d99\u627f\u306e\u968e\u5c64\u306f3\u5c64\u4ee5\u4e0a\u306b\u306a\u3089\u306a\u3044\u3088\u3046\u306b\u3059\u308b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-65\">\n<li>\u62bd\u8c61\u30af\u30e9\u30b9\u3084\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u6d3b\u7528\u3057\u3066\u3001\u67d4\u8edf\u306a\u8a2d\u8a08\u3092\u884c\u3046<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-66\">\n<li><code>final<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u306f\u3001\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u304c\u91cd\u8981\u306a\u5834\u9762\u3084\u3001\u8a2d\u8a08\u306e\u610f\u56f3\u3092\u660e\u78ba\u306b\u3057\u305f\u3044\u5834\u5408\u306b\u4f7f\u7528\u3059\u308b<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n<\/div>\n\n<div id=\"sgb-css-id-68\">\n<p>\u3053\u308c\u3089\u306e\u30d9\u30b9\u30c8\u30d7\u30e9\u30af\u30c6\u30a3\u30b9\u3092\u610f\u8b58\u3059\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u4fdd\u5b88\u6027\u304c\u9ad8\u304f\u3001\u62e1\u5f35\u3057\u3084\u3059\u3044Java\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u8a2d\u8a08\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-69\">\n<h2 class=\"wp-block-heading\" id=\"i-12\">4. Java extends\u3068\u4ed6\u306eOOP\u6982\u5ff5\u3068\u306e\u95a2\u4fc2\u6027<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-70\">\n<p>Java\u306e<code>extends<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u306f\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\uff08OOP\uff09\u306e\u91cd\u8981\u306a\u6982\u5ff5\u306e\u4e00\u3064\u3067\u3059\u304c\u3001\u4ed6\u306eOOP\u6982\u5ff5\u3068\u3082\u5bc6\u63a5\u306b\u95a2\u9023\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001<code>extends<\/code>\u3068\u4ed6\u306eOOP\u6982\u5ff5\u3068\u306e\u95a2\u4fc2\u6027\u306b\u3064\u3044\u3066\u8a73\u3057\u304f\u898b\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-71\">\n<h3 class=\"wp-block-heading\" id=\"i-13\">4.1. \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3068\u306e\u9055\u3044\uff1aimplements\u3068extends\u306e\u4f7f\u3044\u5206\u3051<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-72\">\n<p>Java\u3067\u306f\u3001\u30af\u30e9\u30b9\u306e\u7d99\u627f\u306b\u306f<code>extends<\/code>\u3092\u3001\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u5b9f\u88c5\u306b\u306f<code>implements<\/code>\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002\u3053\u306e2\u3064\u306e\u6982\u5ff5\u306f\u7570\u306a\u308b\u76ee\u7684\u3092\u6301\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\"><code>extends<\/code> \u3068 <code>implements<\/code><\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\"><div id=\"sgb-css-id-79\">\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-75\">\n<li><code>extends<\/code>\uff08\u7d99\u627f\uff09\uff1a\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-73\">\n<li>\u65e2\u5b58\u306e\u30af\u30e9\u30b9\u306e\u7279\u6027\u3092\u5f15\u304d\u7d99\u304e\u3001\u65b0\u3057\u3044\u30af\u30e9\u30b9\u3092\u4f5c\u6210\u3057\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-74\">\n<li>\u5358\u4e00\u7d99\u627f\u306e\u307f\u3092\u30b5\u30dd\u30fc\u30c8\u3057\u307e\u3059\uff081\u3064\u306e\u30af\u30e9\u30b9\u3057\u304b\u7d99\u627f\u3067\u304d\u307e\u305b\u3093\uff09\u3002<\/li>\n<\/div>\n\n\n<li>\u30e1\u30bd\u30c3\u30c9\u3001\u30d5\u30a3\u30fc\u30eb\u30c9\u3001\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u7d99\u627f\u3067\u304d\u307e\u3059\u3002<\/li>\n<\/ul>\n<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-78\">\n<li><code>implements<\/code>\uff08\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u5b9f\u88c5\uff09\uff1a\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-76\">\n<li>\u30af\u30e9\u30b9\u304c\u7279\u5b9a\u306e\u632f\u308b\u821e\u3044\u3092\u4fdd\u8a3c\u3059\u308b\u3053\u3068\u3092\u5ba3\u8a00\u3057\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-77\">\n<li>\u591a\u91cd\u5b9f\u88c5\u304c\u53ef\u80fd\u3067\u3059\uff08\u8907\u6570\u306e\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9f\u88c5\u3067\u304d\u307e\u3059\uff09\u3002<\/li>\n<\/div>\n\n\n<li>\u30e1\u30bd\u30c3\u30c9\u306e\u4ed5\u69d8\u306e\u307f\u3092\u5b9a\u7fa9\u3057\u3001\u5b9f\u88c5\u306f\u30af\u30e9\u30b9\u3067\u884c\u3044\u307e\u3059\u3002<\/li>\n<\/ul>\n<\/li>\n<\/div><\/ul>\n<\/div><\/div><\/div>\n\n\n<div id=\"sgb-css-id-80\">\n<p>\u4ee5\u4e0b\u306e\u4f8b\u3067\u306f\u3001<code>Fish<\/code>\u30af\u30e9\u30b9\u304c<code>Animal<\/code>\u30af\u30e9\u30b9\u3092\u7d99\u627f\uff08<code>extends<\/code>\uff09\u3057\u3001<code>Swimmable<\/code>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9f\u88c5\uff08<code>implements<\/code>\uff09\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001<code>Fish<\/code>\u306f<code>Animal<\/code>\u306e\u7279\u6027\u3092\u7d99\u627f\u3057\u3064\u3064\u3001<code>Swimmable<\/code>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3067\u5b9a\u7fa9\u3055\u308c\u305f\u632f\u308b\u821e\u3044\u3092\u4fdd\u8a3c\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">interface Swimmable {\n    void swim();\n}\n\nclass Animal {\n    void eat() {\n        System.out.println(\"Animal is eating\");\n    }\n}\n\nclass Fish extends Animal implements Swimmable {\n    @Override\n    public void swim() {\n        System.out.println(\"Fish is swimming\");\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-81\">\n<h3 class=\"wp-block-heading\" id=\"i-14\">4.2. \u62bd\u8c61\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3059\u308b\uff1a\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\u30d1\u30bf\u30fc\u30f3<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-82\">\n<p>\u62bd\u8c61\u30af\u30e9\u30b9\u306f\u3001<code>extends<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4f7f\u7528\u3057\u3066\u7d99\u627f\u3055\u308c\u308b\u7279\u6b8a\u306a\u30af\u30e9\u30b9\u3067\u3059\u3002\u62bd\u8c61\u30af\u30e9\u30b9\u306f\u3001\u5171\u901a\u306e\u632f\u308b\u821e\u3044\u3092\u5b9a\u7fa9\u3057\u3064\u3064\u3001\u4e00\u90e8\u306e\u5b9f\u88c5\u3092\u5b50\u30af\u30e9\u30b9\u306b\u59d4\u306d\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3053\u308c\u306f\u3001\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\u30d1\u30bf\u30fc\u30f3\u306e\u57fa\u790e\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-83\">\n<p>\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\u30d1\u30bf\u30fc\u30f3\u306f\u3001\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306e\u9aa8\u7d44\u307f\u3092\u5b9a\u7fa9\u3057\u3001\u4e00\u90e8\u306e\u624b\u9806\u3092\u30b5\u30d6\u30af\u30e9\u30b9\u306b\u59d4\u306d\u308b\u30c7\u30b6\u30a4\u30f3\u30d1\u30bf\u30fc\u30f3\u3067\u3059\u3002<\/p>\n<\/div>\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=\"\">abstract class BeverageMaker {\n    \/\/ \u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\n    final void prepareBeverage() {\n        boilWater();\n        brew();\n        pourInCup();\n        if (customerWantsCondiments()) {\n            addCondiments();\n        }\n    }\n\n    abstract void brew();\n    abstract void addCondiments();\n\n    void boilWater() {\n        System.out.println(\"Boiling water\");\n    }\n\n    void pourInCup() {\n        System.out.println(\"Pouring into cup\");\n    }\n\n    boolean customerWantsCondiments() {\n        return true;\n    }\n}\n\nclass CoffeeMaker extends BeverageMaker {\n    @Override\n    void brew() {\n        System.out.println(\"Dripping coffee through filter\");\n    }\n\n    @Override\n    void addCondiments() {\n        System.out.println(\"Adding sugar and milk\");\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-84\">\n<p>\u3053\u306e\u4f8b\u3067\u306f\u3001<code>BeverageMaker<\/code>\u62bd\u8c61\u30af\u30e9\u30b9\u304c\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\uff08<code>prepareBeverage()<\/code>\uff09\u3092\u5b9a\u7fa9\u3057\u3001<code>CoffeeMaker<\/code>\u30af\u30e9\u30b9\u304c\u5177\u4f53\u7684\u306a\u5b9f\u88c5\u3092\u63d0\u4f9b\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-85\">\n<h3 class=\"wp-block-heading\" id=\"i-15\">4.3. \u591a\u91cd\u7d99\u627f\u306e\u5236\u9650\u3068\u305d\u306e\u56de\u907f\u7b56<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-86\">\n<p>Java\u306f\u5358\u4e00\u7d99\u627f\u306e\u307f\u3092\u30b5\u30dd\u30fc\u30c8\u3057\u3066\u304a\u308a\u3001\u3053\u308c\u306f\u30c0\u30a4\u30e4\u30e2\u30f3\u30c9\u554f\u984c\u3092\u56de\u907f\u3059\u308b\u305f\u3081\u3067\u3059\u3002\u3057\u304b\u3057\u3001\u3053\u306e\u5236\u9650\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u56de\u907f\u7b56\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u591a\u91cd\u7d99\u627f\u306e\u5236\u9650\u306e\u56de\u907f\u7b56<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-87\">\n<li>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u591a\u91cd\u5b9f\u88c5<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-88\">\n<li>\u30c7\u30d5\u30a9\u30eb\u30c8\u30e1\u30bd\u30c3\u30c9\u306e\u6d3b\u7528\uff08Java 8\u4ee5\u964d\uff09<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-89\">\n<li>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u306e\u4f7f\u7528<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-90\">\n<p>\u7279\u306b\u3001Java 8\u4ee5\u964d\u3067\u306f\u3001\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306b\u30c7\u30d5\u30a9\u30eb\u30c8\u30e1\u30bd\u30c3\u30c9\u3092\u5b9a\u7fa9\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u901a\u3058\u3066\u7591\u4f3c\u7684\u306a\u591a\u91cd\u7d99\u627f\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">interface Flyable {\n    default void fly() {\n        System.out.println(\"Flying\");\n    }\n}\n\ninterface Swimmable {\n    default void swim() {\n        System.out.println(\"Swimming\");\n    }\n}\n\nclass Duck implements Flyable, Swimmable {\n    \/\/ fly\u30e1\u30bd\u30c3\u30c9\u3068swim\u30e1\u30bd\u30c3\u30c9\u3092\u4e21\u65b9\u7d99\u627f\n}<\/pre>\n\n\n<div id=\"sgb-css-id-91\">\n<p>\u305f\u3060\u3057\u3001\u8907\u6570\u306e\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u304b\u3089\u540c\u540d\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30e1\u30bd\u30c3\u30c9\u3092\u7d99\u627f\u3057\u305f\u5834\u5408\u3001\u30b3\u30f3\u30d5\u30ea\u30af\u30c8\u3092\u89e3\u6c7a\u3059\u308b\u305f\u3081\u306b\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u304c\u5fc5\u8981\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">interface A {\n    default void doSomething() {\n        System.out.println(\"Doing something in A\");\n    }\n}\n\ninterface B {\n    default void doSomething() {\n        System.out.println(\"Doing something in B\");\n    }\n}\n\nclass C implements A, B {\n    @Override\n    public void doSomething() {\n        A.super.doSomething(); \/\/ A\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30e1\u30bd\u30c3\u30c9\u3092\u547c\u3073\u51fa\u3059\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-92\">\n<p>\u3053\u308c\u3089\u306e\u6982\u5ff5\u3092\u7406\u89e3\u3057\u9069\u5207\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001Java\u306e\u7d99\u627f\u30e1\u30ab\u30cb\u30ba\u30e0\u3092\u3088\u308a\u52b9\u679c\u7684\u306b\u6d3b\u7528\u3057\u3001\u67d4\u8edf\u3067\u4fdd\u5b88\u6027\u306e\u9ad8\u3044\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-93\">\n<h2 class=\"wp-block-heading\" id=\"i-16\">5. \u5b9f\u52d9\u3067\u306eJava extends\u6d3b\u7528\u8853<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-94\">\n<p>Java\u306e\u7d99\u627f\u6a5f\u80fd\u306f\u3001\u5b9f\u969b\u306e\u958b\u767a\u73fe\u5834\u3067\u69d8\u3005\u306a\u5f62\u3067\u6d3b\u7528\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u306e\u62e1\u5f35\u3001\u30c6\u30b9\u30c8\u99c6\u52d5\u958b\u767a\u3001\u305d\u3057\u3066\u30ec\u30ac\u30b7\u30fc\u30b3\u30fc\u30c9\u306e\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u306b\u304a\u3051\u308b\u7d99\u627f\u306e\u5b9f\u8df5\u7684\u306a\u4f7f\u7528\u65b9\u6cd5\u3092\u898b\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-95\">\n<h3 class=\"wp-block-heading\" id=\"i-17\">5.1. \u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3084\u30e9\u30a4\u30d6\u30e9\u30ea\u306e\u62e1\u5f35\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-96\">\n<p>\u591a\u304f\u306eJava\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3084\u30e9\u30a4\u30d6\u30e9\u30ea\u306f\u3001\u7d99\u627f\u3092\u901a\u3058\u3066\u30ab\u30b9\u30bf\u30de\u30a4\u30ba\u3084\u6a5f\u80fd\u62e1\u5f35\u304c\u3067\u304d\u308b\u3088\u3046\u306b\u8a2d\u8a08\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u4e3b\u306a\u624b\u6cd5\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u3092\u901a\u3058\u305f\u30ab\u30b9\u30bf\u30de\u30a4\u30ba\u3084\u6a5f\u80fd\u62e1\u5f35<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-97\">\n<li>\u65e2\u5b58\u306e\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u3066\u30ab\u30b9\u30bf\u30de\u30a4\u30ba<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-98\">\n<li>\u62bd\u8c61\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u3066\u5177\u4f53\u7684\u306a\u5b9f\u88c5\u3092\u63d0\u4f9b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-99\">\n<li>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9f\u88c5\u3057\u3066\u30d7\u30e9\u30b0\u30a4\u30f3\u7684\u306a\u6a5f\u80fd\u3092\u8ffd\u52a0<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-100\">\n<p>\u4f8b\u3048\u3070\u3001Spring Framework\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u3001<code>JdbcTemplate<\/code>\u3092\u7d99\u627f\u3057\u3066\u30ab\u30b9\u30bf\u30e0\u30c7\u30fc\u30bf\u30a2\u30af\u30bb\u30b9\u30af\u30e9\u30b9\u3092\u4f5c\u6210\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">public class CustomJdbcTemplate extends JdbcTemplate {\n    @Override\n    public &lt;T&gt; T query(String sql, ResultSetExtractor&lt;T&gt; rse) throws DataAccessException {\n        \/\/ \u30ab\u30b9\u30bf\u30e0\u30ed\u30ae\u30f3\u30b0\u3084\u30a8\u30e9\u30fc\u30cf\u30f3\u30c9\u30ea\u30f3\u30b0\u3092\u8ffd\u52a0\n        try {\n            return super.query(sql, rse);\n        } catch (DataAccessException e) {\n            log.error(\"Query execution failed: \" + sql, e);\n            throw e;\n        }\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-101\">\n<p>\u6ce8\u610f\u70b9\u3068\u3057\u3066\u3001\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u30a2\u30c3\u30d7\u306b\u4f34\u3046\u4e92\u63db\u6027\u306e\u554f\u984c\u3084\u3001\u904e\u5ea6\u306e\u7d99\u627f\u306b\u3088\u308b\u30b3\u30fc\u30c9\u306e\u8907\u96d1\u5316\u306b\u6c17\u3092\u3064\u3051\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-102\">\n<h3 class=\"wp-block-heading\" id=\"i-18\">5.2. \u30c6\u30b9\u30c8\u99c6\u52d5\u958b\u767a\uff08TDD\uff09\u306b\u304a\u3051\u308b\u7d99\u627f\u306e\u5229\u7528<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-103\">\n<p>\u30c6\u30b9\u30c8\u99c6\u52d5\u958b\u767a\uff08TDD\uff09\u306b\u304a\u3044\u3066\u3001\u7d99\u627f\u306f\u6b21\u306e\u3088\u3046\u306a\u5229\u70b9\u3092\u3082\u305f\u3089\u3057\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">TDD\u3067\u306e\u7d99\u627f\u306e\u5229\u70b9<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list\"><div id=\"sgb-css-id-104\">\n<li>\u30c6\u30b9\u30c8\u30b3\u30fc\u30c9\u306e\u518d\u5229\u7528\u6027\u5411\u4e0a<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-105\">\n<li>\u5171\u901a\u306e\u30bb\u30c3\u30c8\u30a2\u30c3\u30d7\u3084\u30c6\u30a3\u30a2\u30c0\u30a6\u30f3\u51e6\u7406\u306e\u96c6\u7d04<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-106\">\n<li>\u30c6\u30b9\u30c8\u30b1\u30fc\u30b9\u306e\u968e\u5c64\u69cb\u9020\u5316<\/li>\n<\/div><\/ul>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-107\">\n<p>JUnit\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u3001\u57fa\u672c\u30c6\u30b9\u30c8\u30af\u30e9\u30b9\u3092\u4f5c\u6210\u3057\u3001\u305d\u308c\u3092\u7d99\u627f\u3059\u308b\u3053\u3068\u3067\u52b9\u7387\u7684\u306b\u30c6\u30b9\u30c8\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">public abstract class BaseDAOTest {\n    protected DataSource dataSource;\n\n    @Before\n    public void setUp() throws Exception {\n        \/\/ \u30c7\u30fc\u30bf\u30bd\u30fc\u30b9\u306e\u30bb\u30c3\u30c8\u30a2\u30c3\u30d7\n        dataSource = new EmbeddedDatabaseBuilder()\n            .setType(EmbeddedDatabaseType.H2)\n            .addScript(\"schema.sql\")\n            .addScript(\"test-data.sql\")\n            .build();\n    }\n\n    @After\n    public void tearDown() throws Exception {\n        \/\/ \u30ea\u30bd\u30fc\u30b9\u306e\u30af\u30ea\u30fc\u30f3\u30a2\u30c3\u30d7\n    }\n}\n\npublic class UserDAOTest extends BaseDAOTest {\n    private UserDAO userDAO;\n\n    @Before\n    public void setUp() throws Exception {\n        super.setUp();\n        userDAO = new UserDAO(dataSource);\n    }\n\n    @Test\n    public void testFindUserById() {\n        \/\/ \u30c6\u30b9\u30c8\u30b3\u30fc\u30c9\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-108\">\n<p>\u3053\u306e\u65b9\u6cd5\u306b\u3088\u308a\u3001\u5171\u901a\u306e\u30bb\u30c3\u30c8\u30a2\u30c3\u30d7\u51e6\u7406\u3092\u518d\u5229\u7528\u3057\u3064\u3064\u3001\u500b\u5225\u306e\u30c6\u30b9\u30c8\u306b\u96c6\u4e2d\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-109\">\n<h3 class=\"wp-block-heading\" id=\"i-19\">5.3. \u30ec\u30ac\u30b7\u30fc\u30b3\u30fc\u30c9\u306e\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u3068\u7d99\u627f\u306e\u518d\u8a2d\u8a08<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-110\">\n<p>\u30ec\u30ac\u30b7\u30fc\u30b3\u30fc\u30c9\u306e\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u306b\u304a\u3044\u3066\u3001\u4e0d\u9069\u5207\u306a\u7d99\u627f\u69cb\u9020\u306f\u3057\u3070\u3057\u3070\u554f\u984c\u3068\u306a\u308a\u307e\u3059\u3002\u4e3b\u306a\u8ab2\u984c\u3068\u5bfe\u5fdc\u7b56\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u8ab2\u984c\u3068\u5bfe\u5fdc\u7b56<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-111\">\n<li>\u6df1\u3059\u304e\u308b\u7d99\u627f\u968e\u5c64\n<ul class=\"wp-block-list is-style-sango-list-simple\">\n<li>\u5bfe\u7b56\uff1a\u4e2d\u9593\u62bd\u8c61\u30af\u30e9\u30b9\u306e\u5c0e\u5165\u3084\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u3078\u306e\u7f6e\u304d\u63db\u3048<\/li>\n<\/ul>\n<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-112\">\n<li>\u4e0d\u9069\u5207\u306a\u7d99\u627f\u95a2\u4fc2\n<ul class=\"wp-block-list is-style-sango-list-simple\">\n<li>\u5bfe\u7b56\uff1a\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u62bd\u51fa\u3068\u59d4\u8b72\u30d1\u30bf\u30fc\u30f3\u306e\u9069\u7528<\/li>\n<\/ul>\n<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-114\">\n<li>\u904e\u5ea6\u306b\u5177\u8c61\u7684\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-113\">\n<li>\u5bfe\u7b56\uff1a\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\u30d1\u30bf\u30fc\u30f3\u306e\u9069\u7528<\/li>\n<\/div><\/ul>\n<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-115\">\n<p>\u4f8b\u3048\u3070\u3001\u6b21\u306e\u3088\u3046\u306a\u6df1\u3044\u7d99\u627f\u968e\u5c64\u304c\u3042\u308b\u3068\u3057\u307e\u3059\u3002<\/p>\n<\/div>\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 Vehicle { \/* ... *\/ }\nclass Car extends Vehicle { \/* ... *\/ }\nclass SportsCar extends Car { \/* ... *\/ }\nclass RaceCar extends SportsCar { \/* ... *\/ }<\/pre>\n\n\n<div id=\"sgb-css-id-116\">\n<p>\u3053\u308c\u3092\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">interface Vehicle { \/* ... *\/ }\nclass BasicVehicle implements Vehicle { \/* ... *\/ }\nclass Car implements Vehicle {\n    private BasicVehicle vehicle;\n    \/\/ \u59d4\u8b72\u3092\u4f7f\u7528\n}\nclass SportsCar implements Vehicle {\n    private Car car;\n    \/\/ \u59d4\u8b72\u3092\u4f7f\u7528\n}<\/pre>\n\n\n<div id=\"sgb-css-id-117\">\n<p>\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u6642\u306f\u3001\u65e2\u5b58\u306e\u52d5\u4f5c\u3092\u7dad\u6301\u3057\u306a\u304c\u3089\u6bb5\u968e\u7684\u306b\u884c\u3046\u3053\u3068\u304c\u91cd\u8981\u3067\u3059\u3002\u307e\u305f\u3001\u5341\u5206\u306a\u30c6\u30b9\u30c8\u30ab\u30d0\u30ec\u30c3\u30b8\u3092\u78ba\u4fdd\u3059\u308b\u3053\u3068\u3067\u3001\u5b89\u5168\u306b\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u3092\u9032\u3081\u3089\u308c\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-118\">\n<p>\u3053\u308c\u3089\u306e\u5b9f\u8df5\u7684\u306a\u6d3b\u7528\u6cd5\u3092\u7406\u89e3\u3057\u9069\u7528\u3059\u308b\u3053\u3068\u3067\u3001Java\u306e\u7d99\u627f\u6a5f\u80fd\u3092\u52b9\u679c\u7684\u306b\u5229\u7528\u3057\u3001\u4fdd\u5b88\u6027\u306e\u9ad8\u3044\u5805\u7262\u306a\u30b3\u30fc\u30c9\u3092\u66f8\u304f\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-119\">\n<h2 class=\"wp-block-heading\" id=\"i-20\">6. Java extends\u306e\u843d\u3068\u3057\u7a74\u3068\u5bfe\u7b56<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-120\">\n<p>\u7d99\u627f\u306f\u5f37\u529b\u306a\u6a5f\u80fd\u3067\u3059\u304c\u3001\u9069\u5207\u306b\u4f7f\u7528\u3057\u306a\u3044\u3068\u69d8\u3005\u306a\u554f\u984c\u3092\u5f15\u304d\u8d77\u3053\u3059\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001Java\u306e<code>extends<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4f7f\u7528\u3059\u308b\u969b\u306e\u4e3b\u306a\u843d\u3068\u3057\u7a74\u3068\u3001\u305d\u308c\u3089\u3092\u56de\u907f\u3059\u308b\u305f\u3081\u306e\u5bfe\u7b56\u306b\u3064\u3044\u3066\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-121\">\n<h3 class=\"wp-block-heading\" id=\"i-21\">6.1. \u7d99\u627f\u306e\u4e71\u7528\u304c\u3082\u305f\u3089\u3059\u554f\u984c\u70b9<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-122\">\n<p>\u7d99\u627f\u3092\u904e\u5270\u306b\u4f7f\u7528\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u554f\u984c\u304c\u767a\u751f\u3059\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u306e\u4e71\u7528\u304c\u3082\u305f\u3089\u3059\u554f\u984c\u70b9<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-123\">\n<li>\u30b3\u30fc\u30c9\u306e\u8907\u96d1\u6027\u5897\u5927<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-124\">\n<li>\u67d4\u8edf\u6027\u306e\u4f4e\u4e0b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-125\">\n<li>\u30ab\u30d7\u30bb\u30eb\u5316\u306e\u7834\u58ca<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-126\">\n<li>\u30c6\u30b9\u30c8\u306e\u56f0\u96e3\u3055<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-127\">\n<p>\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u4e0d\u9069\u5207\u306a\u7d99\u627f\u306e\u4f8b\u3092\u8003\u3048\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n<\/div>\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 Square extends Rectangle {\n    @Override\n    public void setWidth(int width) {\n        super.setWidth(width);\n        super.setHeight(width);\n    }\n\n    @Override\n    public void setHeight(int height) {\n        super.setHeight(height);\n        super.setWidth(height);\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-128\">\n<p>\u3053\u306e\u8a2d\u8a08\u3067\u306f\u3001\u6b63\u65b9\u5f62\u306f\u9577\u65b9\u5f62\u306e\u7279\u6b8a\u306a\u30b1\u30fc\u30b9\u3067\u3042\u308b\u3068\u3044\u3046\u8003\u3048\u306b\u57fa\u3065\u3044\u3066\u3044\u307e\u3059\u304c\u3001\u5b9f\u969b\u306b\u306f\u6b63\u65b9\u5f62\u306e\u632f\u308b\u821e\u3044\u304c\u9577\u65b9\u5f62\u306e\u632f\u308b\u821e\u3044\u3068\u77db\u76fe\u3057\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-129\">\n<p>\u5bfe\u7b56\u3068\u3057\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u30a2\u30d7\u30ed\u30fc\u30c1\u304c\u52b9\u679c\u7684\u3067\u3059\u3002<\/p>\n<\/div>\n\n\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-130\">\n<li>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u306e\u4f7f\u7528<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-131\">\n<li>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u6d3b\u7528<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-132\">\n<li>\u7d99\u627f\u306e\u6df1\u3055\u3092\u5236\u9650\u3059\u308b<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-133\">\n<li>LSP\uff08\u30ea\u30b9\u30b3\u30d5\u306e\u7f6e\u63db\u539f\u5247\uff09\u306e\u9075\u5b88<\/li>\n<\/div><\/ul>\n\n\n<div id=\"sgb-css-id-134\">\n<h3 class=\"wp-block-heading\" id=\"i-22\">6.2. \u8106\u5f31\u306a\u57fa\u5e95\u30af\u30e9\u30b9\u554f\u984c\u3068\u305d\u306e\u89e3\u6c7a\u7b56<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-135\">\n<p>\u8106\u5f31\u306a\u57fa\u5e95\u30af\u30e9\u30b9\u554f\u984c\u3068\u306f\u3001\u57fa\u5e95\u30af\u30e9\u30b9\u306e\u5909\u66f4\u304c\u4e88\u671f\u305b\u306c\u5f62\u3067\u6d3e\u751f\u30af\u30e9\u30b9\u306e\u52d5\u4f5c\u306b\u5f71\u97ff\u3092\u4e0e\u3048\u308b\u554f\u984c\u3067\u3059\u3002\u3053\u306e\u554f\u984c\u306f\u3001\u57fa\u5e95\u30af\u30e9\u30b9\u3068\u6d3e\u751f\u30af\u30e9\u30b9\u306e\u7d50\u5408\u5ea6\u304c\u9ad8\u3044\u5834\u5408\u3084\u3001\u6d3e\u751f\u30af\u30e9\u30b9\u304c\u57fa\u5e95\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\u8a73\u7d30\u306b\u4f9d\u5b58\u3057\u3066\u3044\u308b\u5834\u5408\u306b\u767a\u751f\u3057\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-136\">\n<p>Java 1.2\u4ee5\u524d\u306e<code>Collection<\/code>\u30af\u30e9\u30b9\u3068<code>Hashtable<\/code>\u30af\u30e9\u30b9\u306e\u95a2\u4fc2\u306f\u3001\u3053\u306e\u554f\u984c\u306e\u5178\u578b\u7684\u306a\u4f8b\u3067\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-137\">\n<p>\u89e3\u6c7a\u7b56\u3068\u3057\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u30a2\u30d7\u30ed\u30fc\u30c1\u304c\u6709\u52b9\u3067\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u89e3\u6c7a\u7b56\u306e\u30a2\u30d7\u30ed\u30fc\u30c1<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-138\">\n<li>\u62bd\u8c61\u5316\u30ec\u30d9\u30eb\u306e\u9069\u5207\u306a\u8a2d\u8a08<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-139\">\n<li>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u4f7f\u7528<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-140\">\n<li>\u30c6\u30f3\u30d7\u30ec\u30fc\u30c8\u30e1\u30bd\u30c3\u30c9\u30d1\u30bf\u30fc\u30f3\u306e\u9069\u7528<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-141\">\n<li>\u7d99\u627f\u3088\u308a\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u3092\u512a\u5148<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-142\">\n<p>\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u3001\u57fa\u5e95\u30af\u30e9\u30b9\u306e\u5909\u66f4\u306b\u3088\u308b\u5f71\u97ff\u3092\u6700\u5c0f\u9650\u306b\u6291\u3048\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">interface Shape {\n    double area();\n}\n\nclass Rectangle implements Shape {\n    private double width;\n    private double height;\n\n    \/\/ \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3001getter\u3068setter\n\n    @Override\n    public double area() {\n        return width * height;\n    }\n}\n\nclass Square implements Shape {\n    private double side;\n\n    \/\/ \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3001getter\u3068setter\n\n    @Override\n    public double area() {\n        return side * side;\n    }\n}<\/pre>\n\n\n<div id=\"sgb-css-id-143\">\n<h3 class=\"wp-block-heading\" id=\"i-23\">6.3. \u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3078\u306e\u5f71\u97ff\u3068\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-144\">\n<p>\u7d99\u627f\u306f\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5f71\u97ff\u3092\u4e0e\u3048\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u7d99\u627f\u304c\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306b\u4e0e\u3048\u308b\u5f71\u97ff<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-145\">\n<li>\u30e1\u30e2\u30ea\u4f7f\u7528\u91cf\u306e\u5897\u52a0<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-146\">\n<li>\u30e1\u30bd\u30c3\u30c9\u547c\u3073\u51fa\u3057\u306e\u8907\u96d1\u5316<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-147\">\n<li>\u521d\u671f\u5316\u6642\u9593\u306e\u5897\u52a0<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-148\">\n<p>\u3053\u308c\u3089\u306e\u554f\u984c\u306b\u5bfe\u51e6\u3059\u308b\u305f\u3081\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u3082\u306e\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-153\">\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u554f\u984c\u3078\u306e\u6700\u9069\u5316\u30c6\u30af\u30cb\u30c3\u30af<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-149\">\n<li><code>final<\/code>\u4fee\u98fe\u5b50\u306e\u9069\u5207\u306a\u4f7f\u7528\uff1a\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3055\u308c\u306a\u3044\u30e1\u30bd\u30c3\u30c9\u3092<code>final<\/code>\u306b\u3059\u308b\u3053\u3068\u3067\u3001JVM\u304c\u6700\u9069\u5316\u3057\u3084\u3059\u304f\u306a\u308a\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-150\">\n<li>\u30e1\u30bd\u30c3\u30c9\u306e\u30a4\u30f3\u30e9\u30a4\u30f3\u5316\uff1a\u5c0f\u3055\u306a\u30e1\u30bd\u30c3\u30c9\u3092\u57fa\u5e95\u30af\u30e9\u30b9\u304b\u3089\u6d3e\u751f\u30af\u30e9\u30b9\u306b\u30a4\u30f3\u30e9\u30a4\u30f3\u5316\u3059\u308b\u3053\u3068\u3067\u3001\u30e1\u30bd\u30c3\u30c9\u547c\u3073\u51fa\u3057\u306e\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9\u3092\u6e1b\u3089\u305b\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-151\">\n<li>\u7d99\u627f\u306e\u6df1\u3055\u3092\u5236\u9650\u3059\u308b\uff1a\u7d99\u627f\u968e\u5c64\u304c\u6df1\u304f\u306a\u308a\u3059\u304e\u306a\u3044\u3088\u3046\u6ce8\u610f\u3057\u307e\u3059\u3002<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-152\">\n<li>\u4e0d\u5fc5\u8981\u306a\u7d99\u627f\u306e\u6392\u9664\uff1a\u7d99\u627f\u304c\u672c\u5f53\u306b\u5fc5\u8981\u304b\u3092\u614e\u91cd\u306b\u691c\u8a0e\u3057\u3001\u4e0d\u8981\u306a\u5834\u5408\u306f\u5225\u306e\u8a2d\u8a08\u3092\u9078\u629e\u3057\u307e\u3059\u3002<\/li>\n<\/div><\/ul>\n<\/div><\/div>\n<\/div>\n\n<div id=\"sgb-css-id-154\">\n<p>\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u306e\u554f\u984c\u3092\u7279\u5b9a\u3057\u3001\u6700\u9069\u5316\u306e\u52b9\u679c\u3092\u6e2c\u5b9a\u3059\u308b\u305f\u3081\u306b\u3001JProfiler\u3001VisualVM\u3001Java Flight Recorder\u306a\u3069\u306e\u30c4\u30fc\u30eb\u3092\u6d3b\u7528\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-155\">\n<p>\u7d99\u627f\u306e\u4f7f\u7528\u306b\u306f\u5e38\u306b\u614e\u91cd\u3067\u3042\u308b\u3079\u304d\u3067\u3059\u3002\u9069\u5207\u306b\u4f7f\u7528\u3059\u308c\u3070\u5f37\u529b\u306a\u30c4\u30fc\u30eb\u3068\u306a\u308a\u307e\u3059\u304c\u3001\u4e71\u7528\u3059\u308b\u3068\u4fdd\u5b88\u6027\u306e\u4f4e\u3044\u30b3\u30fc\u30c9\u306b\u3064\u306a\u304c\u308a\u307e\u3059\u3002\u4e0a\u8a18\u306e\u843d\u3068\u3057\u7a74\u3092\u8a8d\u8b58\u3057\u3001\u9069\u5207\u306a\u5bfe\u7b56\u3092\u8b1b\u3058\u308b\u3053\u3068\u3067\u3001\u3088\u308a\u5805\u7262\u3067\u52b9\u7387\u7684\u306aJava\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u8a2d\u8a08\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-156\">\n<h2 class=\"wp-block-heading\" id=\"i-24\">7. Java 17\u4ee5\u964d\u306eextends\u306b\u95a2\u3059\u308b\u65b0\u6a5f\u80fd\u3068\u5c06\u6765\u5c55\u671b<\/h2>\n<\/div>\n\n<div id=\"sgb-css-id-157\">\n<p>Java\u8a00\u8a9e\u306f\u7d99\u7d9a\u7684\u306b\u9032\u5316\u3057\u3066\u304a\u308a\u3001\u7d99\u627f\u306b\u95a2\u3059\u308b\u6a5f\u80fd\u3082\u4f8b\u5916\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002Java 17\u4ee5\u964d\u3001\u7d99\u627f\u306e\u5236\u5fa1\u3068\u6d3b\u7528\u306b\u95a2\u3059\u308b\u65b0\u6a5f\u80fd\u304c\u5c0e\u5165\u3055\u308c\u3001\u3088\u308a\u5b89\u5168\u3067\u8868\u73fe\u529b\u8c4a\u304b\u306a\u30b3\u30fc\u30c9\u304c\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u3053\u308c\u3089\u306e\u65b0\u6a5f\u80fd\u3068\u4eca\u5f8c\u306e\u5c55\u671b\u306b\u3064\u3044\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-158\">\n<h3 class=\"wp-block-heading\" id=\"i-25\">7.1. \u30b7\u30fc\u30eb\u30c9\u30af\u30e9\u30b9\u3068\u7d99\u627f\u306e\u5236\u5fa1<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-159\">\n<p>Java 17\u3067\u5c0e\u5165\u3055\u308c\u305f\u30b7\u30fc\u30eb\u30c9\u30af\u30e9\u30b9\uff08Sealed Classes\uff09\u306f\u3001\u30af\u30e9\u30b9\u306e\u7d99\u627f\u3092\u660e\u793a\u7684\u306b\u5236\u9650\u3059\u308b\u6a5f\u80fd\u3067\u3059\u3002<code>sealed<\/code>\u3001<code>permits<\/code>\u3001<code>non-sealed<\/code>\u3068\u3044\u3046\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4f7f\u7528\u3057\u3066\u3001\u7d99\u627f\u3067\u304d\u308b\u30af\u30e9\u30b9\u3092\u660e\u793a\u7684\u306b\u6307\u5b9a\u3067\u304d\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">public sealed class Shape permits Circle, Rectangle, Square {\n    \/\/ Shape\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\n}\n\npublic final class Circle extends Shape {\n    \/\/ Circle\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\n}\n\npublic non-sealed class Rectangle extends Shape {\n    \/\/ Rectangle\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\n}\n\npublic sealed class Square extends Shape permits ColoredSquare {\n    \/\/ Square\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\n}\n\npublic final class ColoredSquare extends Square {\n    \/\/ ColoredSquare\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\n}<\/pre>\n\n\n<div id=\"sgb-css-id-160\">\n<p>\u3053\u306e\u6a5f\u80fd\u306b\u3088\u308a\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5229\u70b9\u304c\u5f97\u3089\u308c\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<div class=\"wp-block-sgb-block-simple sgb-box-simple sgb-box-simple--title-normal sgb-box-simple--with-border\"><div style=\"background-color:var(--wp--preset--color--sango-main);color:#FFF\" class=\"sgb-box-simple__title\">\u30b7\u30fc\u30eb\u30c9\u30af\u30e9\u30b9\u306e\u5229\u70b9<\/div><div class=\"sgb-box-simple__body\" style=\"border-color:var(--wp--preset--color--sango-main);background-color:#FFF\">\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-161\">\n<li>\u30b3\u30fc\u30c9\u306e\u5b89\u5168\u6027\u3068\u53ef\u8aad\u6027\u306e\u5411\u4e0a<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-162\">\n<li>\u30e9\u30a4\u30d6\u30e9\u30ea\u8a2d\u8a08\u8005\u306b\u3088\u308b\u7d99\u627f\u306e\u53b3\u5bc6\u306a\u5236\u5fa1<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-163\">\n<li>\u30b3\u30f3\u30d1\u30a4\u30e9\u306b\u3088\u308b\u7d99\u627f\u95a2\u4fc2\u306e\u691c\u8a3c<\/li>\n<\/div><\/ol>\n<\/div><\/div>\n\n\n<div id=\"sgb-css-id-164\">\n<p>\u30b7\u30fc\u30eb\u30c9\u30af\u30e9\u30b9\u306f\u3001\u7279\u306b\u660e\u78ba\u306b\u5b9a\u7fa9\u3055\u308c\u305f\u968e\u5c64\u69cb\u9020\u3092\u6301\u3064\u30c9\u30e1\u30a4\u30f3\u30e2\u30c7\u30eb\u306e\u8a2d\u8a08\u306b\u6709\u52b9\u3067\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-165\">\n<h3 class=\"wp-block-heading\" id=\"i-26\">7.2. \u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u3068\u7d99\u627f\u968e\u5c64\u306e\u6271\u3044<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-166\">\n<p>Java 16\u4ee5\u964d\u3001\u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u306e\u6a5f\u80fd\u304c\u6bb5\u968e\u7684\u306b\u5c0e\u5165\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u7d99\u627f\u968e\u5c64\u3092\u8003\u616e\u3057\u305f\u578b\u30c1\u30a7\u30c3\u30af\u3068\u30ad\u30e3\u30b9\u30c8\u304c\u7c21\u7565\u5316\u3055\u308c\u307e\u3057\u305f\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-167\">\n<p>\u4f8b\u3048\u3070\u3001<code>instanceof<\/code>\u6f14\u7b97\u5b50\u306e\u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u3092\u4f7f\u7528\u3059\u308b\u3068\u3001\u6b21\u306e\u3088\u3046\u306b\u66f8\u3051\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">Shape shape = getShape();\nif (shape instanceof Rectangle r &amp;&amp; r.width() &gt; 100) {\n    System.out.println(\"\u5e45\u306e\u5e83\u3044\u9577\u65b9\u5f62\u3067\u3059: \" + r.width());\n} else if (shape instanceof Circle c) {\n    System.out.println(\"\u5186\u306e\u534a\u5f84: \" + c.radius());\n}<\/pre>\n\n\n<div id=\"sgb-css-id-168\">\n<p>\u3055\u3089\u306b\u3001Java 18\u4ee5\u964d\u306e\u30d7\u30ec\u30d3\u30e5\u30fc\u6a5f\u80fd\u3068\u3057\u3066\u3001switch\u5f0f\u306b\u304a\u3051\u308b\u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u3082\u5c0e\u5165\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\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=\"\">double area = switch (shape) {\n    case Rectangle r -&gt; r.width() * r.height();\n    case Circle c -&gt; Math.PI * c.radius() * c.radius();\n    case Triangle t -&gt; t.base() * t.height() \/ 2;\n    default -&gt; throw new IllegalArgumentException(\"Unknown shape\");\n};<\/pre>\n\n\n<div id=\"sgb-css-id-169\">\n<p>\u3053\u308c\u3089\u306e\u6a5f\u80fd\u306b\u3088\u308a\u3001\u7d99\u627f\u968e\u5c64\u3092\u8003\u616e\u3057\u305f\u30b3\u30fc\u30c9\u304c\u3088\u308a\u7c21\u6f54\u306b\u3001\u305d\u3057\u3066\u5b89\u5168\u306b\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n<div id=\"sgb-css-id-170\">\n<h3 class=\"wp-block-heading\" id=\"i-27\">7.3. \u4eca\u5f8c\u306eJava\u8a00\u8a9e\u4ed5\u69d8\u306b\u304a\u3051\u308b\u7d99\u627f\u306e\u4f4d\u7f6e\u3065\u3051<\/h3>\n<\/div>\n\n<div id=\"sgb-css-id-171\">\n<p>Java\u306e\u8a00\u8a9e\u4ed5\u69d8\u306b\u304a\u3051\u308b\u7d99\u627f\u306e\u4f4d\u7f6e\u3065\u3051\u306f\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u50be\u5411\u3067\u9032\u5316\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<ol class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-172\">\n<li>\u7d99\u627f\u306e\u5236\u5fa1\u3068\u5b89\u5168\u6027\u306e\u5f37\u5316<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-173\">\n<li>\u30b3\u30f3\u30dd\u30b8\u30b7\u30e7\u30f3\u3068\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u91cd\u8981\u6027\u306e\u5897\u52a0<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-174\">\n<li>\u95a2\u6570\u578b\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u3068\u306e\u878d\u5408<\/li>\n<\/div><\/ol>\n\n\n<div id=\"sgb-css-id-175\">\n<p>\u4eca\u5f8c\u3001\u691c\u8a0e\u3055\u308c\u3066\u3044\u308b\u6a5f\u80fd\u306b\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u3082\u306e\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<\/div>\n\n\n<ul class=\"wp-block-list is-style-sango-list-simple\"><div id=\"sgb-css-id-176\">\n<li>\u30d0\u30ea\u30e5\u30fc\u30af\u30e9\u30b9\uff08\u5024\u578b\uff09\uff1a\u30d7\u30ea\u30df\u30c6\u30a3\u30d6\u578b\u306e\u3088\u3046\u306a\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3068\u53c2\u7167\u578b\u306e\u3088\u3046\u306a\u67d4\u8edf\u6027\u3092\u517c\u306d\u5099\u3048\u305f\u30af\u30e9\u30b9<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-177\">\n<li>\u30d1\u30bf\u30fc\u30f3\u30de\u30c3\u30c1\u30f3\u30b0\u306e\u3055\u3089\u306a\u308b\u62e1\u5f35\uff1a\u3088\u308a\u8907\u96d1\u306a\u6761\u4ef6\u3084\u69cb\u9020\u306b\u5bfe\u5fdc\u3057\u305f\u30de\u30c3\u30c1\u30f3\u30b0<\/li>\n<\/div>\n\n<div id=\"sgb-css-id-178\">\n<li>\u591a\u91cd\u7d99\u627f\u306e\u90e8\u5206\u7684\u30b5\u30dd\u30fc\u30c8\uff1a\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30e1\u30bd\u30c3\u30c9\u3092\u62e1\u5f35\u3057\u305f\u5f62\u3067\u306e\u591a\u91cd\u7d99\u627f\uff08\u8b70\u8ad6\u6bb5\u968e\uff09<\/li>\n<\/div><\/ul>\n\n\n<div 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