{"id":253,"date":"2026-07-17T11:13:42","date_gmt":"2026-07-17T03:13:42","guid":{"rendered":"http:\/\/ssjava.xyz\/index.php\/2026\/07\/17\/13-java-inheritance-basics\/"},"modified":"2026-07-17T11:21:27","modified_gmt":"2026-07-17T03:21:27","slug":"13-%e7%bb%a7%e6%89%bf%e5%9f%ba%e7%a1%80%ef%bc%9a%e4%bb%8e%e5%a4%8d%e7%94%a8%e5%88%b0%e5%b1%82%e6%ac%a1-java-%e7%bb%a7%e6%89%bf%e7%9a%84%e6%9c%ac%e8%b4%a8","status":"publish","type":"post","link":"https:\/\/ssjava.xyz\/index.php\/2026\/07\/17\/13-%e7%bb%a7%e6%89%bf%e5%9f%ba%e7%a1%80%ef%bc%9a%e4%bb%8e%e5%a4%8d%e7%94%a8%e5%88%b0%e5%b1%82%e6%ac%a1-java-%e7%bb%a7%e6%89%bf%e7%9a%84%e6%9c%ac%e8%b4%a8\/","title":{"rendered":"13. \u7ee7\u627f\u57fa\u7840\uff1a\u4ece&#8221;\u590d\u7528&#8221;\u5230&#8221;\u5c42\u6b21&#8221;\u2014\u2014Java \u7ee7\u627f\u7684\u672c\u8d28"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5047\u8bbe\u4f60\u8981\u5f00\u53d1\u4e00\u4e2a\u5458\u5de5\u7ba1\u7406\u7cfb\u7edf\u3002\u5f20\u4e09\u662f\u4e00\u540d\u666e\u901a\u5458\u5de5\uff0c\u674e\u56db\u662f\u4e00\u540d\u7ecf\u7406\uff0c\u738b\u4e94\u662f\u4e00\u540d\u6280\u672f\u603b\u76d1\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u666e\u901a\u5458\u5de5\u6709\uff1a\u59d3\u540d\u3001\u5de5\u53f7\u3001\u5de5\u8d44\u3001\u6253\u5361\u3001\u9886\u5de5\u8d44<\/li>\n\n\n\n<li>\u7ecf\u7406\u6709\uff1a\u59d3\u540d\u3001\u5de5\u53f7\u3001\u5de5\u8d44\u3001\u6253\u5361\u3001\u9886\u5de5\u8d44\u3001\u7ba1\u7406\u56e2\u961f\u3001\u5ba1\u6279\u62a5\u9500<\/li>\n\n\n\n<li>\u6280\u672f\u603b\u76d1\u6709\uff1a\u59d3\u540d\u3001\u5de5\u53f7\u3001\u5de5\u8d44\u3001\u6253\u5361\u3001\u9886\u5de5\u8d44\u3001\u5236\u5b9a\u6280\u672f\u65b9\u6848\u3001\u9762\u8bd5\u5019\u9009\u4eba<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u5199\u4e09\u4e2a\u72ec\u7acb\u7c7b\uff0c\u4f60\u4f1a\u5199\u51fa\u5927\u91cf<strong>\u91cd\u590d\u4ee3\u7801<\/strong>\u2014\u2014\u4e09\u4e2a\u7c7b\u90fd\u6709\u59d3\u540d\u3001\u5de5\u53f7\u3001\u5de5\u8d44\uff0c\u90fd\u6709\u6253\u5361\u548c\u9886\u5de5\u8d44\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e0d\u5408\u7406\u3002\u73b0\u5b9e\u4e16\u754c\u4e2d&#8221;\u7ecf\u7406&#8221;\u662f&#8221;\u5458\u5de5&#8221;\u7684\u4e00\u79cd\u7279\u6b8a\u7c7b\u578b\u2014\u2014\u7ecf\u7406&#8221;<strong>\u662f<\/strong>&#8220;\uff08is-a\uff09\u5458\u5de5\uff0c\u53ea\u662f\u6bd4\u666e\u901a\u5458\u5de5\u591a\u4e86\u67d0\u4e9b\u529f\u80fd\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u7ee7\u627f<\/strong>\u6b63\u662f\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u800c\u5b58\u5728\u7684\uff1a\u628a\u516c\u5171\u5c5e\u6027\u548c\u65b9\u6cd5\u62bd\u53d6\u5230\u7236\u7c7b\uff08\u57fa\u7c7b\/\u8d85\u7c7b\uff09\uff0c\u5b50\u7c7b\uff08\u6d3e\u751f\u7c7b\uff09\u901a\u8fc7 <code>extends<\/code> \u5173\u952e\u5b57\u7ee7\u627f\u7236\u7c7b\uff0c\u5e76\u5728\u6b64\u57fa\u7840\u4e0a\u6269\u5c55\u81ea\u5df1\u7684\u7279\u6027\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e3a\u4ec0\u4e48\u9700\u8981\u7ee7\u627f<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u7f16\u5199\u4e86\u524d\u4e09\u7bc7\u7c7b\u4e0e\u5bf9\u8c61\u7684\u5185\u5bb9\u540e\uff0c\u4f60\u5df2\u7ecf\u4f1a\u7528\u7c7b\u6765\u63cf\u8ff0\u73b0\u5b9e\u4e16\u754c\u7684\u5b9e\u4f53\u3002\u4f46\u9047\u5230\u591a\u4e2a\u7c7b\u6709<strong>\u5171\u6027<\/strong>\u65f6\uff0c\u9010\u4e2a\u7f16\u5199\u4f1a\u5bfc\u81f4\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4ee3\u7801\u5197\u4f59<\/strong>\u2014\u2014\u540c\u6837\u7684\u5b57\u6bb5\u548c\u65b9\u6cd5\u5728\u591a\u4e2a\u7c7b\u4e2d\u91cd\u590d<\/li>\n\n\n\n<li><strong>\u7ef4\u62a4\u56f0\u96be<\/strong>\u2014\u2014\u4fee\u6539\u516c\u5171\u903b\u8f91\u9700\u8981\u5230\u5904\u540c\u6b65<\/li>\n\n\n\n<li><strong>\u6269\u5c55\u6027\u5dee<\/strong>\u2014\u2014\u65b0\u589e\u4e00\u79cd\u5458\u5de5\u7c7b\u578b\u53c8\u5f97\u590d\u5236\u4e00\u904d<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ee7\u627f\u8ba9\u4ee3\u7801<strong>\u53ef\u590d\u7528\u3001\u53ef\u6269\u5c55\u3001\u80fd\u5206\u5c42<\/strong>\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><code>extends<\/code> \u5173\u952e\u5b57\u4e0e\u7ee7\u627f\u8bed\u6cd5<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Java \u4f7f\u7528 <code>extends<\/code> \u5173\u952e\u5b57\u5b9e\u73b0\u7ee7\u627f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u57fa\u672c\u8bed\u6cd5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u7236\u7c7b\nclass Employee {\n    String name;\n    int id;\n    double salary;\n\n    void punchClock() {\n        System.out.println(name + \" \u6253\u5361\u4e0a\u73ed\");\n    }\n\n    void getPaid() {\n        System.out.println(name + \" \u9886\u53d6\u5de5\u8d44\uff1a\" + salary);\n    }\n}\n\n\/\/ \u5b50\u7c7b\u7ee7\u627f\u7236\u7c7b\nclass Manager extends Employee {\n    int teamSize;\n\n    void manageTeam() {\n        System.out.println(name + \" \u7ba1\u7406 \" + teamSize + \" \u4eba\u56e2\u961f\");\n    }\n\n    void approveExpense() {\n        System.out.println(name + \" \u5ba1\u6279\u62a5\u9500\");\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 <code>Manager<\/code> \u6ca1\u6709\u5b9a\u4e49 <code>name<\/code>\u3001<code>salary<\/code>\u3001<code>punchClock()<\/code>\uff0c\u4f46\u8fd9\u4e9b\u5b83\u90fd\u6709\u2014\u2014\u4ece <code>Employee<\/code> \u7ee7\u627f\u800c\u6765\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u6d4b\u8bd5\u7ee7\u627f<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>public class InheritanceDemo {\n    public static void main(String&#91;] args) {\n        Manager mgr = new Manager();\n        mgr.name = \"\u674e\u56db\";       \/\/ \u7ee7\u627f\u81ea Employee\n        mgr.salary = 25000;      \/\/ \u7ee7\u627f\u81ea Employee\n        mgr.teamSize = 8;        \/\/ \u81ea\u5df1\u7684\u5b57\u6bb5\n\n        mgr.punchClock();        \/\/ \u7ee7\u627f\u81ea Employee\n        mgr.manageTeam();        \/\/ \u81ea\u5df1\u7684\u65b9\u6cd5\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8f93\u51fa\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u674e\u56db \u6253\u5361\u4e0a\u73ed\n\u674e\u56db \u7ba1\u7406 8 \u4eba\u56e2\u961f<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u7ee7\u627f\u7684\u6838\u5fc3\u7279\u6027<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u2460 \u5b50\u7c7b\u62e5\u6709\u7236\u7c7b\u6240\u6709\u7684\u975e private \u6210\u5458<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u8bbf\u95ee\u4fee\u9970\u7b26<\/th><th>\u5f53\u524d\u7c7b<\/th><th>\u540c\u5305<\/th><th>\u5b50\u7c7b<\/th><th>\u5176\u4ed6\u5305<\/th><\/tr><\/thead><tbody><tr><td><code>private<\/code><\/td><td>\u2705<\/td><td>\u274c<\/td><td>\u274c<\/td><td>\u274c<\/td><\/tr><tr><td>\u9ed8\u8ba4\uff08\u5305\u7ea7\uff09<\/td><td>\u2705<\/td><td>\u2705<\/td><td>\u274c<\/td><td>\u274c<\/td><\/tr><tr><td><code>protected<\/code><\/td><td>\u2705<\/td><td>\u2705<\/td><td>\u2705<\/td><td>\u274c<\/td><\/tr><tr><td><code>public<\/code><\/td><td>\u2705<\/td><td>\u2705<\/td><td>\u2705<\/td><td>\u2705<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u5b50\u7c7b\u65e0\u6cd5\u7ee7\u627f <code>private<\/code> \u6210\u5458<\/strong>\uff0c\u4f46\u53ef\u4ee5\u901a\u8fc7\u7236\u7c7b\u63d0\u4f9b\u7684 <code>public\/protected<\/code> \u65b9\u6cd5\u95f4\u63a5\u8bbf\u95ee\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u2461 Java \u53ea\u652f\u6301\u5355\u7ee7\u627f<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>class A extends B, C { }  \/\/ \u274c \u7f16\u8bd1\u9519\u8bef\uff01Java \u4e0d\u652f\u6301\u591a\u7ee7\u627f<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u4e2a\u5b50\u7c7b\u53ea\u80fd\u6709\u4e00\u4e2a\u76f4\u63a5\u7236\u7c7b\u3002\u90a3\u5982\u679c\u786e\u5b9e\u9700\u8981&#8221;\u591a\u91cd\u7279\u6027&#8221;\u600e\u4e48\u529e\uff1f\u540e\u7eed\u6587\u7ae0\u4f1a\u8bb2\u2014\u2014\u63a5\u53e3\uff08interface\uff09\u53ef\u4ee5\u89e3\u51b3\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u2462 \u7ee7\u627f\u5173\u7cfb\u662f &#8220;is-a&#8221; \u5173\u7cfb<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u9002\u7528\u573a\u666f\u7528\u4e00\u53e5\u8bdd\u5224\u65ad\uff1a<strong>\u5b50\u7c7b is-a \u7236\u7c7b<\/strong>\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Manager is-a Employee?  \u2705 \u6210\u7acb\nDog is-a Animal?        \u2705 \u6210\u7acb\nCircle is-a Shape?      \u2705 \u6210\u7acb<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u5982\u679c\u8fd9\u53e5\u8bdd\u8bfb\u4e0d\u901a\uff0c\u5c31\u4e0d\u5e94\u8be5\u7528\u7ee7\u627f\u2014\u2014\u5e94\u8be5\u7528\u7ec4\u5408\uff08\u540e\u9762\u4f1a\u8be6\u7ec6\u8bb2\uff09\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u2463 \u4f20\u9012\u6027<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>class A { }\nclass B extends A { }\nclass C extends B { }<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>C<\/code> \u7ee7\u627f\u4e86 <code>B<\/code> \u7684\u6240\u6709\u975e\u79c1\u6709\u6210\u5458\uff0c<code>B<\/code> \u7ee7\u627f\u4e86 <code>A<\/code> \u7684\u6240\u6709\u975e\u79c1\u6709\u6210\u5458\u2014\u2014\u6240\u4ee5 <code>C<\/code> \u95f4\u63a5\u4e5f\u62e5\u6709 <code>A<\/code> \u7684\u6210\u5458\u3002\u8fd9\u53eb<strong>\u591a\u5c42\u7ee7\u627f<\/strong>\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u6bcf\u4e2a\u7c7b\u90fd\u9690\u5f0f\u7ee7\u627f Object<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f60\u53ef\u80fd\u6ca1\u5199\u8fc7 <code>extends<\/code>\uff0c\u4f46\u6bcf\u4e2a Java \u7c7b\u90fd<strong>\u9ed8\u8ba4\u7ee7\u627f<\/strong> <code>java.lang.Object<\/code>\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>class MyClass { }           \/\/ \u7b49\u4ef7\u4e8e class MyClass extends Object { }<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>Object<\/code> \u63d0\u4f9b\u4e86\u51e0\u4e2a\u6240\u6709\u5bf9\u8c61\u90fd\u6709\u7684\u65b9\u6cd5\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u65b9\u6cd5<\/th><th>\u4f5c\u7528<\/th><\/tr><\/thead><tbody><tr><td><code>toString()<\/code><\/td><td>\u8fd4\u56de\u5bf9\u8c61\u7684\u5b57\u7b26\u4e32\u8868\u793a<\/td><\/tr><tr><td><code>equals(Object obj)<\/code><\/td><td>\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\u662f\u5426&#8221;\u76f8\u7b49&#8221;<\/td><\/tr><tr><td><code>hashCode()<\/code><\/td><td>\u8fd4\u56de\u5bf9\u8c61\u7684\u54c8\u5e0c\u7801<\/td><\/tr><tr><td><code>getClass()<\/code><\/td><td>\u8fd4\u56de\u5bf9\u8c61\u7684\u8fd0\u884c\u65f6\u7c7b\u4fe1\u606f<\/td><\/tr><tr><td><code>clone()<\/code><\/td><td>\u521b\u5efa\u5e76\u8fd4\u56de\u5bf9\u8c61\u7684\u4e00\u4e2a\u526f\u672c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<pre class=\"wp-block-code\"><code>public class ObjectDemo {\n    public static void main(String&#91;] args) {\n        Employee emp = new Employee();\n        System.out.println(emp.toString());  \/\/ \u6765\u81ea Object\n        System.out.println(emp.getClass());  \/\/ \u6765\u81ea Object\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8f93\u51fa\u7c7b\u4f3c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Employee@1b6d3586\nclass Employee<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>toString()<\/code> \u9ed8\u8ba4\u8f93\u51fa&#8221;\u7c7b\u540d@\u54c8\u5e0c\u503c&#8221;\u2014\u2014\u540e\u7eed\u6587\u7ae0\u4f1a\u8bb2\u5982\u4f55<strong>\u91cd\u5199<\/strong>\u5b83\uff0c\u8ba9\u5b83\u8f93\u51fa\u66f4\u6709\u610f\u4e49\u7684\u4fe1\u606f\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\ud83d\udca1 <strong>\u601d\u8003<\/strong>\uff1a\u65e2\u7136\u6240\u6709\u7c7b\u90fd\u7ee7\u627f <code>Object<\/code>\uff0c\u90a3 <code>int<\/code>\u3001<code>double<\/code> \u7b49\u57fa\u672c\u7c7b\u578b\u5462\uff1f\u5b83\u4eec\u4e0d\u662f\u7c7b\uff0c\u4e0d\u7ee7\u627f <code>Object<\/code>\u3002\u4f46\u5b83\u4eec\u7684\u5305\u88c5\u7c7b\uff08<code>Integer<\/code>\u3001<code>Double<\/code>\uff09\u7ee7\u627f <code>Object<\/code>\u2014\u2014\u7b2c \u2467 \u7bc7\u4f1a\u8bb2\u679a\u4e3e\u4e0e\u5305\u88c5\u7c7b\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">\u7ee7\u627f vs \u7ec4\u5408\uff08Composition\uff09<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u662f\u4e00\u4e2a\u5e38\u88ab\u5ffd\u89c6\u7684<strong>\u8bbe\u8ba1\u601d\u8003\u9898<\/strong>\u3002\u5f88\u591a\u521d\u5b66\u8005\u4e00\u53d1\u73b0\u7ee7\u627f\u597d\u7528\u5c31\u5230\u5904\u7528\uff0c\u4f46\u5176\u5b9e<strong>\u4f18\u5148\u4f7f\u7528\u7ec4\u5408\uff0c\u8c28\u614e\u4f7f\u7528\u7ee7\u627f<\/strong>\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u4ec0\u4e48\u662f\u7ec4\u5408\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ec4\u5408\u5c31\u662f\u5728\u4e00\u4e2a\u7c7b\u4e2d\u6301\u6709\u53e6\u4e00\u4e2a\u7c7b\u7684\u5f15\u7528\uff0c\u8868\u793a&#8221;<strong>has-a<\/strong>&#8220;\u5173\u7cfb\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u7ec4\u5408 - \u6c7d\u8f66\u6709\u5f15\u64ce\nclass Engine {\n    void start() { System.out.println(\"\u5f15\u64ce\u542f\u52a8\"); }\n}\n\nclass Car {\n    private Engine engine = new Engine();  \/\/ \u7ec4\u5408\n\n    void start() {\n        engine.start();\n        System.out.println(\"\u6c7d\u8f66\u542f\u52a8\");\n    }\n}<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u4ec0\u4e48\u65f6\u5019\u7528\u7ee7\u627f\uff0c\u4ec0\u4e48\u65f6\u5019\u7528\u7ec4\u5408\uff1f<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u573a\u666f<\/th><th>\u7528\u7ee7\u627f<\/th><th>\u7528\u7ec4\u5408<\/th><th>\u539f\u56e0<\/th><\/tr><\/thead><tbody><tr><td>\u7ecf\u7406&#8221;\u662f&#8221;\u4e00\u79cd\u5458\u5de5<\/td><td>\u2705<\/td><td><\/td><td>is-a \u5173\u7cfb<\/td><\/tr><tr><td>\u6c7d\u8f66&#8221;\u6709&#8221;\u5f15\u64ce<\/td><td><\/td><td>\u2705<\/td><td>has-a \u5173\u7cfb<\/td><\/tr><tr><td>\u9700\u8981\u590d\u7528\u4e00\u4e2a\u7c7b\u7684\u5b9e\u73b0<\/td><td><\/td><td>\u2705<\/td><td>\u7ec4\u5408\u66f4\u7075\u6d3b\uff0c\u4e0d\u7834\u574f\u5c01\u88c5<\/td><\/tr><tr><td>\u9700\u8981\u5229\u7528\u591a\u6001\uff08\u540e\u7eed\u7bc7\u8bb2\uff09<\/td><td>\u2705<\/td><td><\/td><td>\u591a\u6001\u4f9d\u8d56\u7ee7\u627f<\/td><\/tr><tr><td>\u53ea\u60f3\u590d\u7528\u4ee3\u7801\uff0c\u4e0d\u662f\u8868\u8fbeis-a<\/td><td><\/td><td>\u2705<\/td><td>\u7ec4\u5408\u662f\u66f4\u597d\u7684\u91cd\u7528\u65b9\u5f0f<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e00\u4e2a\u53cd\u4f8b<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u274c \u4e0d\u8981\u4e3a\u4e86\u590d\u7528 getTotalPrice() \u5c31\u8ba9 Order \u7ee7\u627f ArrayList\nclass Order extends ArrayList&lt;Item&gt; { ... }<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><code>Order<\/code> \u4e0d\u662f\u4e00\u79cd <code>ArrayList<\/code>\u2014\u2014\u5b83\u662f&#8221;\u8ba2\u5355\u6709\u5546\u54c1\u5217\u8868&#8221;\uff0c\u5e94\u8be5\u7528\u7ec4\u5408\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u2705 \u7ec4\u5408\u66f4\u5408\u7406\nclass Order {\n    private List&lt;Item&gt; items = new ArrayList&lt;&gt;();\n    \/\/ ...\n}<\/code><\/pre>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\ud83d\udca1 \u4e00\u53e5\u8bdd\u539f\u5219\uff1a<strong>\u7ee7\u627f\u662f\u7528\u6765\u8868\u8fbe&#8221;\u662f\u4ec0\u4e48&#8221;\u7684\uff0c\u4e0d\u662f\u7528\u6765&#8221;\u62ff\u4ee3\u7801&#8221;\u7684\u3002<\/strong><\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">\u672c\u7bc7\u5c0f\u7ed3<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4eca\u5929\u4f60\u5b66\u5230\u4e86\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7ee7\u627f\u7684\u672c\u8d28<\/strong>\u2014\u2014\u901a\u8fc7 <code>extends<\/code> \u5173\u952e\u5b57\u8ba9\u5b50\u7c7b\u590d\u7528\u7236\u7c7b\u7684\u975e\u79c1\u6709\u6210\u5458\uff0c\u8868\u8fbe is-a \u5173\u7cfb<\/li>\n\n\n\n<li><strong>\u8bed\u6cd5<\/strong>\u2014\u2014<code>class Manager extends Employee<\/code> \u5373\u53ef\u5b8c\u6210\u7ee7\u627f<\/li>\n\n\n\n<li><strong>\u8bbf\u95ee\u6027<\/strong>\u2014\u2014\u5b50\u7c7b\u53ef\u4ee5\u8bbf\u95ee\u7236\u7c7b\u7684 <code>public<\/code> \u548c <code>protected<\/code> \u6210\u5458\uff0c\u4e0d\u80fd\u8bbf\u95ee <code>private<\/code><\/li>\n\n\n\n<li><strong>\u5355\u7ee7\u627f<\/strong>\u2014\u2014Java \u4e00\u4e2a\u5b50\u7c7b\u53ea\u80fd\u6709\u4e00\u4e2a\u76f4\u63a5\u7236\u7c7b<\/li>\n\n\n\n<li><strong>Object \u7956\u5148<\/strong>\u2014\u2014\u6240\u6709\u7c7b\u9ed8\u8ba4\u7ee7\u627f <code>java.lang.Object<\/code><\/li>\n\n\n\n<li><strong>\u7ee7\u627f vs \u7ec4\u5408<\/strong>\u2014\u2014\u80fd\u7528\u7ec4\u5408\u4f18\u5148\u7528\u7ec4\u5408\uff0c\u7ee7\u627f\u53ea\u7528\u5728 is-a \u573a\u666f<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u4e0b\u4e00\u7bc7\u9884\u544a\uff1a<\/strong> \u7ee7\u627f\u4e0d\u80fd\u53ea\u9760\u7ee7\u627f\u5b57\u6bb5\u548c\u65b9\u6cd5\u2014\u2014\u5b50\u7c7b\u5bf9\u8c61\u5982\u4f55\u521d\u59cb\u5316\uff1f\u7236\u7c7b\u6784\u9020\u5668\u548c\u5b50\u7c7b\u6784\u9020\u5668\u8c01\u5148\u6267\u884c\uff1f<code>super<\/code> \u5173\u952e\u5b57\u5982\u4f55\u7075\u6d3b\u8c03\u7528\u7236\u7c7b\u6210\u5458\uff1f<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0b\u4e00\u7bc7 <strong>\u300a\u7ee7\u627f\u8fdb\u9636\uff1asuper \u5173\u952e\u5b57\u4e0e\u6784\u9020\u5668\u94fe\u300b<\/strong>\uff0c\u5e26\u4f60\u6df1\u5165\u7ee7\u627f\u7684\u5e95\u5c42\u673a\u5236\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5047\u8bbe\u4f60\u8981\u5f00\u53d1\u4e00\u4e2a\u5458\u5de5\u7ba1\u7406\u7cfb\u7edf\u3002\u5f20\u4e09\u662f\u4e00\u540d\u666e\u901a\u5458\u5de5\uff0c\u674e\u56db\u662f\u4e00\u540d\u7ecf\u7406\uff0c\u738b\u4e94\u662f\u4e00\u540d\u6280\u672f\u603b\u76d1\u3002 \u5199\u4e09\u4e2a\u72ec\u7acb\u7c7b\uff0c\u4f60\u4f1a\u5199\u51fa [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35,66],"tags":[],"class_list":["post-253","post","type-post","status-publish","format-standard","hentry","category-03-","category-02-inheritance"],"_links":{"self":[{"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/posts\/253","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/comments?post=253"}],"version-history":[{"count":2,"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/posts\/253\/revisions"}],"predecessor-version":[{"id":256,"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/posts\/253\/revisions\/256"}],"wp:attachment":[{"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/media?parent=253"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/categories?post=253"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ssjava.xyz\/index.php\/wp-json\/wp\/v2\/tags?post=253"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}