{"id":3322,"date":"2025-03-29T17:13:07","date_gmt":"2025-03-29T09:13:07","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3322"},"modified":"2025-03-29T17:13:07","modified_gmt":"2025-03-29T09:13:07","slug":"c-%e5%8a%a8%e6%80%81%e5%86%85%e5%ad%98%e7%ae%a1%e7%90%86","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/29\/c-%e5%8a%a8%e6%80%81%e5%86%85%e5%ad%98%e7%ae%a1%e7%90%86\/","title":{"rendered":"C++ \u52a8\u6001\u5185\u5b58\u7ba1\u7406"},"content":{"rendered":"\n

\u5728 C++ \u4e2d\uff0c\u52a8\u6001\u5185\u5b58\u7ba1\u7406\u5141\u8bb8\u5728\u7a0b\u5e8f\u8fd0\u884c\u65f6\u5206\u914d\u548c\u91ca\u653e\u5185\u5b58\u7a7a\u95f4\u3002\u4e0e\u9759\u6001\u5185\u5b58\u5206\u914d\u4e0d\u540c\uff0c\u52a8\u6001\u5185\u5b58\u5206\u914d\u7684\u5185\u5b58\u5927\u5c0f\u53ef\u4ee5\u6839\u636e\u7a0b\u5e8f\u7684\u9700\u8981\u6765\u51b3\u5b9a\uff0c\u8fd9\u4e3a\u7f16\u7a0b\u63d0\u4f9b\u4e86\u66f4\u5927\u7684\u7075\u6d3b\u6027\u3002C++ \u63d0\u4f9b\u4e86\u4e24\u79cd\u4e3b\u8981\u7684\u64cd\u4f5c\u6765\u7ba1\u7406\u52a8\u6001\u5185\u5b58\uff1anew<\/code> \u548c delete<\/code>\u3002<\/p>\n\n\n\n

1. \u52a8\u6001\u5185\u5b58\u5206\u914d<\/strong><\/h2>\n\n\n\n

1.1 \u4f7f\u7528 new<\/code> \u64cd\u4f5c\u7b26<\/strong><\/h3>\n\n\n\n

new<\/code> \u64cd\u4f5c\u7b26\u7528\u4e8e\u5728\u5806\uff08heap\uff09\u4e0a\u5206\u914d\u5185\u5b58\uff0c\u5e76\u8fd4\u56de\u6307\u5411\u8be5\u5185\u5b58\u7684\u6307\u9488\u3002\u4e0e\u5728\u6808\u4e0a\u5206\u914d\u5185\u5b58\u4e0d\u540c\uff0c\u5806\u4e0a\u7684\u5185\u5b58\u53ef\u4ee5\u5728\u6574\u4e2a\u7a0b\u5e8f\u751f\u547d\u5468\u671f\u4e2d\u8bbf\u95ee\uff0c\u76f4\u5230\u624b\u52a8\u91ca\u653e\u3002<\/p>\n\n\n\n

\u5206\u914d\u5355\u4e2a\u5bf9\u8c61\u7684\u5185\u5b58<\/strong><\/h4>\n\n\n\n
#include <iostream>\nusing namespace std;\n\nint main() {\n    int* p = new int;  \/\/ \u5206\u914d\u4e00\u4e2a int \u7c7b\u578b\u7684\u5185\u5b58\u7a7a\u95f4\n    *p = 5;  \/\/ \u4e3a\u8fd9\u4e2a\u5185\u5b58\u4f4d\u7f6e\u8d4b\u503c\n    cout << \"Value: \" << *p << endl;  \/\/ \u8f93\u51fa\uff1aValue: 5\n\n    delete p;  \/\/ \u91ca\u653e\u5185\u5b58\n    return 0;\n}<\/code><\/pre>\n\n\n\n
\u8bf4\u660e\uff1a<\/strong><\/p>\n\n\n\n
    \n
  • new int<\/code>\uff1a\u5728\u5806\u4e0a\u5206\u914d\u4e00\u4e2a int<\/code> \u7c7b\u578b\u7684\u5185\u5b58\u7a7a\u95f4\u3002<\/li>\n\n\n\n
  • delete p<\/code>\uff1a\u91ca\u653e\u4e4b\u524d\u901a\u8fc7 new<\/code> \u5206\u914d\u7684\u5185\u5b58\u3002<\/li>\n<\/ul>\n\n\n\n
    \u5206\u914d\u6570\u7ec4\u7684\u5185\u5b58<\/strong><\/h4>\n\n\n\n
    #include <iostream>\nusing namespace std;\n\nint main() {\n    int* arr = new int[5];  \/\/ \u5206\u914d\u4e00\u4e2a\u5305\u542b 5 \u4e2a\u6574\u6570\u7684\u6570\u7ec4\n\n    \/\/ \u7ed9\u6570\u7ec4\u8d4b\u503c\n    for (int i = 0; i < 5; ++i) {\n        arr[i] = i * 10;\n    }\n\n    \/\/ \u8f93\u51fa\u6570\u7ec4\u5143\u7d20\n    for (int i = 0; i < 5; ++i) {\n        cout << arr[i] << \" \";\n    }\n    cout << endl;\n\n    delete[] arr;  \/\/ \u91ca\u653e\u6570\u7ec4\u7684\u5185\u5b58\n    return 0;\n}<\/code><\/pre>\n\n\n\n
    \u8bf4\u660e\uff1a<\/strong><\/p>\n\n\n\n
      \n
    • new int[5]<\/code>\uff1a\u5206\u914d\u4e00\u4e2a\u5305\u542b 5 \u4e2a\u6574\u6570\u7684\u52a8\u6001\u6570\u7ec4\u3002<\/li>\n\n\n\n
    • delete[] arr<\/code>\uff1a\u91ca\u653e\u901a\u8fc7 new[]<\/code> \u5206\u914d\u7684\u6570\u7ec4\u5185\u5b58\u3002<\/li>\n<\/ul>\n\n\n\n
      1.2 \u4f7f\u7528 new<\/code> \u8fd4\u56de\u7684\u6307\u9488<\/strong><\/h3>\n\n\n\n
      \u5f53\u4f60\u4f7f\u7528 new<\/code> \u5206\u914d\u5185\u5b58\u65f6\uff0c\u5b83\u8fd4\u56de\u4e00\u4e2a\u6307\u5411\u5df2\u5206\u914d\u5185\u5b58\u7684\u6307\u9488\u3002\u5982\u679c\u5185\u5b58\u5206\u914d\u5931\u8d25\uff08\u4f8b\u5982\uff0c\u5185\u5b58\u4e0d\u8db3\uff09\uff0cnew<\/code> \u4f1a\u629b\u51fa std::bad_alloc<\/code> \u5f02\u5e38\u3002<\/p>\n\n\n\n
      #include <iostream>\n#include <new>  \/\/ \u5305\u542b std::bad_alloc\nusing namespace std;\n\nint main() {\n    try {\n        int* p = new int[10000000000];  \/\/ \u5c1d\u8bd5\u5206\u914d\u4e00\u4e2a\u5de8\u5927\u7684\u6570\u7ec4\n    }\n    catch (const bad_alloc& e) {\n        cout << \"Memory allocation failed: \" << e.what() << endl;\n    }\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
      \u8bf4\u660e\uff1a<\/strong><\/p>\n\n\n\n
        \n
      • std::bad_alloc<\/code>\uff1a\u5982\u679c\u5185\u5b58\u5206\u914d\u5931\u8d25\uff0cnew<\/code> \u4f1a\u629b\u51fa\u6b64\u5f02\u5e38\u3002<\/li>\n<\/ul>\n\n\n\n
        2. \u52a8\u6001\u5185\u5b58\u91ca\u653e<\/strong><\/h2>\n\n\n\n
        \u5728 C++ \u4e2d\uff0c\u4f7f\u7528 new<\/code> \u5206\u914d\u7684\u5185\u5b58\u5fc5\u987b\u624b\u52a8\u91ca\u653e\uff0c\u5426\u5219\u4f1a\u53d1\u751f\u5185\u5b58\u6cc4\u6f0f\uff08memory leak\uff09\u3002\u91ca\u653e\u5185\u5b58\u4f7f\u7528 delete<\/code>\uff08\u5355\u4e2a\u5bf9\u8c61\uff09\u6216 delete[]<\/code>\uff08\u6570\u7ec4\uff09\u64cd\u4f5c\u7b26\u3002<\/p>\n\n\n\n
        2.1 \u91ca\u653e\u5355\u4e2a\u5bf9\u8c61\u7684\u5185\u5b58<\/strong><\/h3>\n\n\n\n
        #include <iostream>\nusing namespace std;\n\nint main() {\n    int* p = new int(10);  \/\/ \u5206\u914d\u5e76\u521d\u59cb\u5316\u5185\u5b58\n    cout << \"Value: \" << *p << endl;  \/\/ \u8f93\u51fa\uff1aValue: 10\n\n    delete p;  \/\/ \u91ca\u653e\u5185\u5b58\n    return 0;\n}<\/code><\/pre>\n\n\n\n
        2.2 \u91ca\u653e\u6570\u7ec4\u7684\u5185\u5b58<\/strong><\/h3>\n\n\n\n
        #include <iostream>\nusing namespace std;\n\nint main() {\n    int* arr = new int[3] {1, 2, 3};  \/\/ \u5206\u914d\u5e76\u521d\u59cb\u5316\u6570\u7ec4\n\n    for (int i = 0; i < 3; ++i) {\n        cout << arr[i] << \" \";  \/\/ \u8f93\u51fa\uff1a1 2 3\n    }\n    cout << endl;\n\n    delete[] arr;  \/\/ \u91ca\u653e\u6570\u7ec4\u5185\u5b58\n    return 0;\n}<\/code><\/pre>\n\n\n\n
        \u6ce8\u610f\uff1a<\/strong><\/p>\n\n\n\n
          \n
        • \u4f7f\u7528 delete<\/code> \u65f6\u8981\u6ce8\u610f\u533a\u5206\u5355\u4e2a\u5bf9\u8c61\u548c\u6570\u7ec4\u5bf9\u8c61\u3002\u5bf9\u4e8e\u6570\u7ec4\u5bf9\u8c61\uff0c\u5fc5\u987b\u4f7f\u7528 delete[]<\/code> \u6765\u91ca\u653e\u5185\u5b58\u3002<\/li>\n<\/ul>\n\n\n\n
          3. C++11 \u667a\u80fd\u6307\u9488<\/strong><\/h2>\n\n\n\n
          C++11 \u5f15\u5165\u4e86\u667a\u80fd\u6307\u9488\uff08std::unique_ptr<\/code> \u548c std::shared_ptr<\/code>\uff09\uff0c\u8fd9\u4e9b\u6307\u9488\u53ef\u4ee5\u81ea\u52a8\u7ba1\u7406\u52a8\u6001\u5206\u914d\u7684\u5185\u5b58\uff0c\u4ece\u800c\u907f\u514d\u624b\u52a8\u7ba1\u7406\u5185\u5b58\u7684\u9ebb\u70e6\u3002<\/p>\n\n\n\n
          3.1 std::unique_ptr<\/code><\/strong><\/h3>\n\n\n\n
          std::unique_ptr<\/code> \u662f\u4e00\u79cd\u667a\u80fd\u6307\u9488\uff0c\u5b83\u786e\u4fdd\u53ea\u6709\u4e00\u4e2a\u6307\u9488\u53ef\u4ee5\u7ba1\u7406\u67d0\u4e2a\u5185\u5b58\u3002\u79bb\u5f00\u4f5c\u7528\u57df\u65f6\uff0cstd::unique_ptr<\/code> \u4f1a\u81ea\u52a8\u91ca\u653e\u5185\u5b58\u3002<\/p>\n\n\n\n
          #include <iostream>\n#include <memory>\nusing namespace std;\n\nint main() {\n    unique_ptr<int> ptr(new int(10));  \/\/ \u5206\u914d\u5185\u5b58\u5e76\u521d\u59cb\u5316\n    cout << \"Value: \" << *ptr << endl;  \/\/ \u8f93\u51fa\uff1aValue: 10\n\n    \/\/ \u4e0d\u9700\u8981\u663e\u5f0f\u8c03\u7528 delete\uff0cptr \u8d85\u51fa\u4f5c\u7528\u57df\u65f6\u81ea\u52a8\u91ca\u653e\u5185\u5b58\n    return 0;\n}<\/code><\/pre>\n\n\n\n
          3.2 std::shared_ptr<\/code><\/strong><\/h3>\n\n\n\n
          std::shared_ptr<\/code> \u662f\u4e00\u4e2a\u667a\u80fd\u6307\u9488\uff0c\u5b83\u5141\u8bb8\u591a\u4e2a\u6307\u9488\u5171\u4eab\u5bf9\u540c\u4e00\u5757\u5185\u5b58\u7684\u6240\u6709\u6743\u3002\u5185\u5b58\u4f1a\u5728\u6700\u540e\u4e00\u4e2a\u6307\u9488\u79bb\u5f00\u4f5c\u7528\u57df\u65f6\u81ea\u52a8\u91ca\u653e\u3002<\/p>\n\n\n\n
          #include <iostream>\n#include <memory>\nusing namespace std;\n\nint main() {\n    shared_ptr<int> ptr1 = make_shared<int>(20);  \/\/ \u521b\u5efa\u5e76\u521d\u59cb\u5316\u5171\u4eab\u6307\u9488\n    {\n        shared_ptr<int> ptr2 = ptr1;  \/\/ ptr1 \u548c ptr2 \u5171\u4eab\u540c\u4e00\u5757\u5185\u5b58\n        cout << \"Shared value: \" << *ptr2 << endl;  \/\/ \u8f93\u51fa\uff1aShared value: 20\n    }  \/\/ ptr2 \u8d85\u51fa\u4f5c\u7528\u57df\uff0c\u5185\u5b58\u4e0d\u4f1a\u7acb\u5373\u91ca\u653e\uff0c\u56e0\u4e3a ptr1 \u4ecd\u7136\u62e5\u6709\u6240\u6709\u6743\n\n    \/\/ \u5f53 ptr1 \u8d85\u51fa\u4f5c\u7528\u57df\u65f6\uff0c\u5185\u5b58\u624d\u4f1a\u88ab\u91ca\u653e\n    return 0;\n}<\/code><\/pre>\n\n\n\n
          3.3 \u667a\u80fd\u6307\u9488\u4f18\u52bf<\/strong><\/h3>\n\n\n\n
            \n
          • \u81ea\u52a8\u5185\u5b58\u7ba1\u7406<\/strong>\uff1a\u667a\u80fd\u6307\u9488\u80fd\u591f\u81ea\u52a8\u91ca\u653e\u5185\u5b58\uff0c\u907f\u514d\u5185\u5b58\u6cc4\u6f0f\u3002<\/li>\n\n\n\n
          • \u5185\u5b58\u5171\u4eab<\/strong>\uff1astd::shared_ptr<\/code> \u5141\u8bb8\u591a\u4e2a\u5bf9\u8c61\u5171\u4eab\u5bf9\u540c\u4e00\u5757\u5185\u5b58\u7684\u6240\u6709\u6743\u3002<\/li>\n<\/ul>\n\n\n\n
            4. \u5185\u5b58\u6cc4\u6f0f\u548c\u9632\u6b62\u5185\u5b58\u6cc4\u6f0f<\/strong><\/h2>\n\n\n\n
            \u5185\u5b58\u6cc4\u6f0f\u662f\u6307\u7a0b\u5e8f\u5206\u914d\u7684\u5185\u5b58\u672a\u80fd\u53ca\u65f6\u91ca\u653e\uff0c\u5bfc\u81f4\u65e0\u6cd5\u518d\u8bbf\u95ee\u548c\u4f7f\u7528\u8be5\u5185\u5b58\u3002\u8fd9\u4f1a\u5bfc\u81f4\u7a0b\u5e8f\u7684\u5185\u5b58\u5360\u7528\u4e0d\u65ad\u589e\u52a0\uff0c\u6700\u7ec8\u53ef\u80fd\u5bfc\u81f4\u7a0b\u5e8f\u5d29\u6e83\u3002<\/p>\n\n\n\n
            4.1 \u5185\u5b58\u6cc4\u6f0f\u7684\u793a\u4f8b<\/strong><\/h3>\n\n\n\n
            #include <iostream>\nusing namespace std;\n\nint main() {\n    int* p = new int(100);  \/\/ \u52a8\u6001\u5206\u914d\u5185\u5b58\n    \/\/ \u5fd8\u8bb0\u91ca\u653e\u5185\u5b58\uff0c\u5bfc\u81f4\u5185\u5b58\u6cc4\u6f0f\n    return 0;\n}<\/code><\/pre>\n\n\n\n
            \u89e3\u51b3\u65b9\u6848<\/strong>\uff1a<\/p>\n\n\n\n
              \n
            • \u59cb\u7ec8\u786e\u4fdd\u5728\u4f7f\u7528\u5b8c\u52a8\u6001\u5185\u5b58\u540e\u4f7f\u7528 delete<\/code> \u6216 delete[]<\/code> \u91ca\u653e\u5185\u5b58\u3002<\/li>\n\n\n\n
            • \u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u667a\u80fd\u6307\u9488\uff08std::unique_ptr<\/code> \u548c std::shared_ptr<\/code>\uff09\u6765\u7ba1\u7406\u5185\u5b58\uff0c\u51cf\u5c11\u5185\u5b58\u6cc4\u6f0f\u7684\u98ce\u9669\u3002<\/li>\n<\/ul>\n\n\n\n
              5. \u603b\u7ed3<\/strong><\/h2>\n\n\n\n
                \n
              • \u52a8\u6001\u5185\u5b58\u5206\u914d<\/strong>\uff1a\u4f7f\u7528 new<\/code> \u64cd\u4f5c\u7b26\u6765\u5206\u914d\u5185\u5b58\u3002<\/li>\n\n\n\n
              • \u52a8\u6001\u5185\u5b58\u91ca\u653e<\/strong>\uff1a\u4f7f\u7528 delete<\/code>\uff08\u5355\u4e2a\u5bf9\u8c61\uff09\u6216 delete[]<\/code>\uff08\u6570\u7ec4\uff09\u91ca\u653e\u5185\u5b58\u3002<\/li>\n\n\n\n
              • \u667a\u80fd\u6307\u9488<\/strong>\uff1astd::unique_ptr<\/code> \u548c std::shared_ptr<\/code> \u81ea\u52a8\u7ba1\u7406\u52a8\u6001\u5185\u5b58\uff0c\u907f\u514d\u5185\u5b58\u6cc4\u6f0f\u3002<\/li>\n\n\n\n
              • \u5185\u5b58\u6cc4\u6f0f<\/strong>\uff1a\u5982\u679c\u52a8\u6001\u5185\u5b58\u6ca1\u6709\u91ca\u653e\uff0c\u5c31\u4f1a\u53d1\u751f\u5185\u5b58\u6cc4\u6f0f\uff0c\u4f7f\u7528\u667a\u80fd\u6307\u9488\u53ef\u4ee5\u6709\u6548\u9632\u6b62\u8fd9\u79cd\u60c5\u51b5\u3002<\/li>\n<\/ul>\n\n\n\n
                \u901a\u8fc7\u7406\u89e3\u5e76\u4f7f\u7528 C++ \u7684\u52a8\u6001\u5185\u5b58\u7ba1\u7406\u529f\u80fd\uff0c\u4f60\u53ef\u4ee5\u66f4\u52a0\u9ad8\u6548\u5730\u63a7\u5236\u5185\u5b58\u7684\u4f7f\u7528\u548c\u91ca\u653e\uff0c\u4ece\u800c\u63d0\u9ad8\u7a0b\u5e8f\u7684\u6027\u80fd\u548c\u7a33\u5b9a\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
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