{"id":5211,"date":"2023-10-19T21:46:45","date_gmt":"2023-10-19T13:46:45","guid":{"rendered":"http:\/\/blog.coolcoding.cn\/?p=5211"},"modified":"2023-10-21T22:28:50","modified_gmt":"2023-10-21T14:28:50","slug":"c11%e4%b8%ad%e7%9a%84override%e5%85%b3%e9%94%ae%e5%ad%97","status":"publish","type":"post","link":"https:\/\/blog.coolcoding.cn\/?p=5211","title":{"rendered":"C++11\u4e2d\u7684override\u5173\u952e\u5b57"},"content":{"rendered":"\n<p>\u4e00\u53e5\u8bdd\u603b\u7ed3: \u6ca1\u4ec0\u4e48\u7528<\/p>\n\n\n\n<p>\u7528\u6765\u663e\u5f0f\u6307\u793a\u5b50\u7c7bvirtual\u51fd\u6570\u662foverride\u7684, \u52a0\u4e86\u53ef\u8bfb\u6027\u66f4\u597d, \u4e0d\u52a0\u4e00\u6837\u8dd1<\/p>\n\n\n\n<p>\u52a0\u9519\u4e86,\u7f16\u8bd1\u5668\u62a5\u9519; \u8fd9\u6837\u7236\u7c7b\u5220\u4e86virtual\u51fd\u6570\u65f6,\u5b50\u7c7b\u7f16\u8bd1\u5c31\u62a5\u9519\u4e86.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h>\n\nclass ClassA\n{\npublic:\n    virtual void Hello()\n    {\n        printf(\"ClassA.Hello\\n\");\n    }\n    void World()\n    {\n        printf(\"ClassA.World\\n\");\n    }\n};\n\nclass ClassB : public ClassA\n{\npublic:\n    virtual void Hello() \/\/ override - recommend syntax\n    {\n        printf(\"ClassB.Hello\\n\");\n    }\n    void World() \/\/ override - compile error\n    {\n        printf(\"ClassB.World\\n\");\n    }\n};\n\nint main()\n{\n    ClassB* b = new ClassB();\n    ClassA* a = b;\n\n    a->Hello();\n    a->World();\n\n    b->Hello();\n    b->World();\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"990\" height=\"738\" src=\"http:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2023\/10\/image-6.png\" alt=\"\" class=\"wp-image-5214\" srcset=\"https:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2023\/10\/image-6.png 990w, https:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2023\/10\/image-6-300x224.png 300w, https:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2023\/10\/image-6-768x573.png 768w, https:\/\/blog.coolcoding.cn\/wp-content\/uploads\/2023\/10\/image-6-67x50.png 67w\" sizes=\"(max-width: 990px) 100vw, 990px\" \/><\/figure>\n\n\n\n<p>\u5173\u4e8e\u865a\u8868\u5c3e\u5df4\u7684\u7a7a\u95f4\u5360\u7528\u95ee\u9898,\u4ee5\u4e0b\u4ee3\u7801\u53ef\u4ee5\u6307\u8bc1<\/p>\n\n\n\n<p>\u572832\u4f4d\u7cfb\u7edf\u4e0b, \u6709\u865a\u8868\u7684\u4e3a4(32\u5b57\u8282), \u65e0\u865a\u8868\u7684\u4e3a1(4\u5b57\u8282)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#include &lt;stdio.h>\n\nclass ClassA\n{\npublic:\n    virtual void Hello()\n    {\n        printf(\"ClassA.Hello\\n\");\n    }\n    void World()\n    {\n        printf(\"ClassA.World\\n\");\n    }\n};\n\nclass ClassB : public ClassA\n{\npublic:\n    virtual void Hello() \/\/ override - recommend syntax\n    {\n        printf(\"ClassB.Hello\\n\");\n    }\n    void World() \/\/ override - compile error\n    {\n        printf(\"ClassB.World\\n\");\n    }\n};\n\nclass ClassC\n{\npublic:\n    void World()\n    {\n        printf(\"ClassC.World\\n\");\n    }\n};\n\nint main()\n{\n    ClassB* b = new ClassB();\n    unsigned int add1 = (unsigned int)(b);\n    b++;\n    unsigned int size1 = (unsigned int)(b) - add1;\n\n    ClassC* c = new ClassC();\n    add1 = (unsigned int)(c);\n    c++;\n    unsigned int size2 = (unsigned int)(c)- add1;\n\n    printf(\"%d, %d\\n\", size1, size2);\n\n    return 0;\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u4e00\u53e5\u8bdd\u603b\u7ed3: \u6ca1\u4ec0\u4e48\u7528 \u7528\u6765\u663e\u5f0f\u6307\u793a\u5b50\u7c7bvirtual\u51fd\u6570\u662foverride\u7684, \u52a0\u4e86\u53ef\u8bfb\u6027\u66f4\u597d, \u4e0d\u52a0\u4e00\u6837\u8dd1 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts\/5211"}],"collection":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5211"}],"version-history":[{"count":4,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts\/5211\/revisions"}],"predecessor-version":[{"id":5216,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=\/wp\/v2\/posts\/5211\/revisions\/5216"}],"wp:attachment":[{"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.coolcoding.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}