{"id":3247,"date":"2025-03-27T23:56:49","date_gmt":"2025-03-27T15:56:49","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3247"},"modified":"2025-03-27T23:56:49","modified_gmt":"2025-03-27T15:56:49","slug":"c-%e4%bf%ae%e9%a5%b0%e7%ac%a6%e7%b1%bb%e5%9e%8b%ef%bc%88modifiers-in-c%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/27\/c-%e4%bf%ae%e9%a5%b0%e7%ac%a6%e7%b1%bb%e5%9e%8b%ef%bc%88modifiers-in-c%ef%bc%89\/","title":{"rendered":"C++ \u4fee\u9970\u7b26\u7c7b\u578b\uff08Modifiers in C++\uff09"},"content":{"rendered":"\n

\u5728 C++ \u4e2d\uff0c\u4fee\u9970\u7b26\uff08Modifiers\uff09\u7528\u4e8e\u6539\u53d8\u6216\u4fee\u9970\u53d8\u91cf\u3001\u51fd\u6570\u6216\u7c7b\u7684\u884c\u4e3a\u548c\u5c5e\u6027\u3002\u4fee\u9970\u7b26\u901a\u8fc7\u589e\u52a0\u9644\u52a0\u7684\u7279\u6027\u6216\u9650\u5236\uff0c\u5f71\u54cd\u53d8\u91cf\u7684\u5b58\u50a8\u7c7b\u578b\u3001\u5927\u5c0f\u3001\u7b26\u53f7\u6216\u51fd\u6570\u7684\u5c5e\u6027\u3002\u5e38\u89c1\u7684\u4fee\u9970\u7b26\u7c7b\u578b\u5305\u62ec const<\/code><\/strong>\u3001volatile<\/code><\/strong>\u3001signed<\/code><\/strong>\u3001unsigned<\/code><\/strong>\u3001long<\/code><\/strong>\u3001short<\/code><\/strong> \u548c mutable<\/code><\/strong> \u7b49\u3002<\/p>\n\n\n\n

\n\n\n\n

1. const<\/code> \u4fee\u9970\u7b26<\/strong><\/h2>\n\n\n\n

const<\/code> \u4fee\u9970\u7b26\u7528\u4e8e\u58f0\u660e\u5e38\u91cf\uff0c\u8868\u793a\u53d8\u91cf\u7684\u503c\u4e0d\u53ef\u66f4\u6539\u3002\u5e38\u91cf\u4e00\u65e6\u521d\u59cb\u5316\uff0c\u503c\u5c06\u4e0d\u80fd\u88ab\u4fee\u6539\u3002const<\/code> \u53ef\u4ee5\u7528\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b\u3001\u6307\u9488\u3001\u7c7b\u6210\u5458\u7b49\u3002<\/p>\n\n\n\n

1.1 \u793a\u4f8b\uff1a\u4f7f\u7528 const<\/code> \u4fee\u9970\u7b26<\/strong><\/h3>\n\n\n\n
#include <iostream>\nusing namespace std;\n\nint main() {\n    const int x = 10;  \/\/ \u5e38\u91cf\u53d8\u91cf\n    \/\/ x = 20;  \/\/ \u9519\u8bef\uff1a\u65e0\u6cd5\u4fee\u6539\u5e38\u91cf\n    cout << \"x: \" << x << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
\u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
x: 10<\/code><\/pre>\n\n\n\n
    \n
  • const<\/code> \u4fee\u9970\u7684\u53d8\u91cf\u4e00\u65e6\u8d4b\u503c\u540e\uff0c\u4e0d\u80fd\u4fee\u6539\u5176\u503c\u3002<\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n
    2. volatile<\/code> \u4fee\u9970\u7b26<\/strong><\/h2>\n\n\n\n
    volatile<\/code> \u7528\u4e8e\u4fee\u9970\u4e00\u4e2a\u53d8\u91cf\uff0c\u544a\u8bc9\u7f16\u8bd1\u5668\u8be5\u53d8\u91cf\u53ef\u80fd\u4f1a\u5728\u7a0b\u5e8f\u7684\u4e0d\u540c\u5730\u65b9\u88ab\u610f\u5916\u5730\u4fee\u6539\uff08\u4f8b\u5982\u786c\u4ef6\u4e2d\u65ad\u6216\u5176\u4ed6\u7ebf\u7a0b\u4fee\u6539\uff09\uff0c\u56e0\u6b64\u7f16\u8bd1\u5668\u4e0d\u8981\u5bf9\u5176\u8fdb\u884c\u4f18\u5316\u3002\u5b83\u544a\u8bc9\u7f16\u8bd1\u5668\uff0c\u6bcf\u6b21\u8bbf\u95ee\u8fd9\u4e2a\u53d8\u91cf\u65f6\u90fd\u5fc5\u987b\u91cd\u65b0\u8bfb\u53d6\u5176\u503c\u3002<\/p>\n\n\n\n
    2.1 \u793a\u4f8b\uff1a\u4f7f\u7528 volatile<\/code> \u4fee\u9970\u7b26<\/strong><\/h3>\n\n\n\n
    #include <iostream>\nusing namespace std;\n\nvolatile int flag = 0;  \/\/ \u544a\u8bc9\u7f16\u8bd1\u5668\u53d8\u91cf\u53ef\u80fd\u88ab\u5916\u90e8\u4fee\u6539\n\nint main() {\n    while (flag == 0) {\n        \/\/ \u5047\u8bbe flag \u5728\u67d0\u4e2a\u5916\u90e8\u4e8b\u4ef6\uff08\u5982\u786c\u4ef6\u4e2d\u65ad\uff09\u53d1\u751f\u65f6\u4fee\u6539\n    }\n    cout << \"Flag modified!\" << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
    \u8bf4\u660e\uff1a<\/strong><\/p>\n\n\n\n
      \n
    • volatile<\/code> \u4fee\u9970\u7b26\u9632\u6b62\u7f16\u8bd1\u5668\u5bf9 flag<\/code> \u8fdb\u884c\u4f18\u5316\uff0c\u4fdd\u8bc1\u6bcf\u6b21\u90fd\u8bfb\u53d6\u6700\u65b0\u503c\u3002<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      3. signed<\/code> \u548c unsigned<\/code> \u4fee\u9970\u7b26<\/strong><\/h2>\n\n\n\n
      signed<\/code> \u548c unsigned<\/code> \u7528\u4e8e\u6539\u53d8\u6574\u578b\u53d8\u91cf\u7684\u7b26\u53f7\u5c5e\u6027\u3002signed<\/code> \u8868\u793a\u6709\u7b26\u53f7\u6574\u6570\uff0c\u53ef\u4ee5\u8868\u793a\u8d1f\u6570\u548c\u6b63\u6570\uff0c\u800c unsigned<\/code> \u8868\u793a\u65e0\u7b26\u53f7\u6574\u6570\uff0c\u4ec5\u80fd\u8868\u793a\u6b63\u6570\u3002<\/p>\n\n\n\n
      3.1 \u793a\u4f8b\uff1a\u4f7f\u7528 signed<\/code> \u548c unsigned<\/code><\/strong><\/h3>\n\n\n\n
      #include <iostream>\nusing namespace std;\n\nint main() {\n    signed int a = -10;  \/\/ \u6709\u7b26\u53f7\u6574\u578b\n    unsigned int b = 20; \/\/ \u65e0\u7b26\u53f7\u6574\u578b\n    cout << \"a: \" << a << \", b: \" << b << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
      \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
      a: -10, b: 20<\/code><\/pre>\n\n\n\n
        \n
      • signed<\/code> \u6574\u578b\u53ef\u4ee5\u5305\u542b\u8d1f\u6570\u548c\u6b63\u6570\uff0c\u800c unsigned<\/code> \u6574\u578b\u4ec5\u5305\u542b\u975e\u8d1f\u6570\uff08\u6b63\u6570\u548c\u96f6\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n
        4. long<\/code> \u548c short<\/code> \u4fee\u9970\u7b26<\/strong><\/h2>\n\n\n\n
        long<\/code> \u548c short<\/code> \u7528\u4e8e\u4fee\u6539\u6574\u6570\u7c7b\u578b\u7684\u5927\u5c0f\u3002long<\/code> \u4f7f\u5f97\u6574\u578b\u6570\u636e\u5360\u7528\u66f4\u5927\u7684\u5185\u5b58\uff0c\u800c short<\/code> \u5219\u4f7f\u5f97\u6570\u636e\u5360\u7528\u66f4\u5c0f\u7684\u5185\u5b58\u3002<\/p>\n\n\n\n
        4.1 \u793a\u4f8b\uff1a\u4f7f\u7528 long<\/code> \u548c short<\/code><\/strong><\/h3>\n\n\n\n
        #include <iostream>\nusing namespace std;\n\nint main() {\n    short int shortVar = 32000;  \/\/ \u77ed\u6574\u578b\n    long int longVar = 123456789; \/\/ \u957f\u6574\u578b\n\n    cout << \"shortVar: \" << shortVar << \", longVar: \" << longVar << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
        \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
        shortVar: 32000, longVar: 123456789<\/code><\/pre>\n\n\n\n
          \n
        • short<\/code> \u5360\u7528 2 \u5b57\u8282\uff08\u901a\u5e38\u4e3a 16 \u4f4d\uff09\uff0clong<\/code> \u5360\u7528 4 \u6216 8 \u5b57\u8282\uff08\u4f9d\u8d56\u4e8e\u5e73\u53f0\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n
          5. mutable<\/code> \u4fee\u9970\u7b26<\/strong><\/h2>\n\n\n\n
          mutable<\/code> \u4fee\u9970\u7b26\u7528\u4e8e\u4fee\u9970\u7c7b\u7684\u6210\u5458\u53d8\u91cf\uff0c\u5141\u8bb8\u5728 const<\/code> \u6210\u5458\u51fd\u6570\u4e2d\u4fee\u6539\u8be5\u6210\u5458\u53d8\u91cf\u7684\u503c\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0cconst<\/code> \u6210\u5458\u51fd\u6570\u65e0\u6cd5\u4fee\u6539\u6210\u5458\u53d8\u91cf\u7684\u503c\uff0c\u4f46\u5982\u679c\u8be5\u6210\u5458\u53d8\u91cf\u88ab mutable<\/code> \u4fee\u9970\uff0c\u5b83\u4ecd\u7136\u53ef\u4ee5\u88ab\u4fee\u6539\u3002<\/p>\n\n\n\n
          5.1 \u793a\u4f8b\uff1a\u4f7f\u7528 mutable<\/code> \u4fee\u9970\u7b26<\/strong><\/h3>\n\n\n\n
          #include <iostream>\nusing namespace std;\n\nclass MyClass {\npublic:\n    mutable int counter = 0;\n\n    void increment() const {  \/\/ const \u6210\u5458\u51fd\u6570\n        counter++;  \/\/ \u53ef\u4ee5\u4fee\u6539 mutable \u6210\u5458\n    }\n\n    int getCounter() const {\n        return counter;\n    }\n};\n\nint main() {\n    MyClass obj;\n    obj.increment();\n    cout << \"Counter: \" << obj.getCounter() << endl;  \/\/ \u8f93\u51fa 1\n    return 0;\n}<\/code><\/pre>\n\n\n\n
          \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
          Counter: 1<\/code><\/pre>\n\n\n\n
            \n
          • counter<\/code> \u88ab\u58f0\u660e\u4e3a mutable<\/code>\uff0c\u56e0\u6b64\u5b83\u53ef\u4ee5\u5728 const<\/code> \u6210\u5458\u51fd\u6570\u4e2d\u4fee\u6539\u3002<\/li>\n<\/ul>\n\n\n\n
            \n\n\n\n
            6. inline<\/code> \u4fee\u9970\u7b26<\/strong><\/h2>\n\n\n\n
            inline<\/code> \u7528\u4e8e\u58f0\u660e\u5185\u8054\u51fd\u6570\u3002\u5b83\u63d0\u793a\u7f16\u8bd1\u5668\u5c06\u51fd\u6570\u8c03\u7528\u66ff\u6362\u4e3a\u51fd\u6570\u4f53\uff0c\u4ee5\u51cf\u5c11\u51fd\u6570\u8c03\u7528\u7684\u5f00\u9500\u3002\u8fd9\u901a\u5e38\u7528\u4e8e\u8f83\u5c0f\u7684\u51fd\u6570\uff0c\u5c24\u5176\u662f\u5355\u884c\u51fd\u6570\u3002<\/p>\n\n\n\n
            6.1 \u793a\u4f8b\uff1a\u4f7f\u7528 inline<\/code> \u4fee\u9970\u7b26<\/strong><\/h3>\n\n\n\n
            #include <iostream>\nusing namespace std;\n\ninline int add(int a, int b) {\n    return a + b;\n}\n\nint main() {\n    cout << \"Sum: \" << add(3, 4) << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
            \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
            Sum: 7<\/code><\/pre>\n\n\n\n
              \n
            • inline<\/code> \u63d0\u793a\u7f16\u8bd1\u5668\u5c3d\u53ef\u80fd\u5c06 add<\/code> \u51fd\u6570\u5c55\u5f00\u6210\u4ee3\u7801\uff0c\u51cf\u5c11\u51fd\u6570\u8c03\u7528\u7684\u5f00\u9500\u3002<\/li>\n<\/ul>\n\n\n\n
              \n\n\n\n
              7. \u603b\u7ed3<\/strong><\/h2>\n\n\n\n
              C++ \u63d0\u4f9b\u4e86\u591a\u79cd\u4fee\u9970\u7b26\uff0c\u53ef\u4ee5\u5728\u58f0\u660e\u53d8\u91cf\u3001\u51fd\u6570\u3001\u7c7b\u65f6\u63d0\u4f9b\u4e0d\u540c\u7684\u884c\u4e3a\u3002\u5e38\u89c1\u7684\u4fee\u9970\u7b26\u5305\u62ec\uff1a<\/p>\n\n\n\n
              \u4fee\u9970\u7b26<\/th>\u8bf4\u660e<\/th>\u793a\u4f8b<\/th><\/tr><\/thead>
              const<\/code><\/td>\u58f0\u660e\u5e38\u91cf\uff0c\u503c\u4e0d\u53ef\u4fee\u6539<\/td>const int x = 10;<\/code><\/td><\/tr>
              volatile<\/code><\/td>\u9632\u6b62\u7f16\u8bd1\u5668\u4f18\u5316\uff0c\u4fdd\u8bc1\u6bcf\u6b21\u8bfb\u53d6\u53d8\u91cf\u7684\u6700\u65b0\u503c<\/td>volatile int flag;<\/code><\/td><\/tr>
              signed<\/code><\/td>\u6709\u7b26\u53f7\u6574\u6570\uff0c\u5141\u8bb8\u8d1f\u6570\u503c<\/td>signed int x = -5;<\/code><\/td><\/tr>
              unsigned<\/code><\/td>\u65e0\u7b26\u53f7\u6574\u6570\uff0c\u53ea\u80fd\u8868\u793a\u975e\u8d1f\u6570<\/td>unsigned int y = 10;<\/code><\/td><\/tr>
              long<\/code><\/td>\u957f\u6574\u578b\uff0c\u901a\u5e38\u5360\u7528\u8f83\u5927\u7684\u5185\u5b58<\/td>long int z = 100000000;<\/code><\/td><\/tr>
              short<\/code><\/td>\u77ed\u6574\u578b\uff0c\u5360\u7528\u8f83\u5c0f\u5185\u5b58<\/td>short int a = 1000;<\/code><\/td><\/tr>
              mutable<\/code><\/td>\u5141\u8bb8\u5728 const<\/code> \u6210\u5458\u51fd\u6570\u4e2d\u4fee\u6539\u6210\u5458\u53d8\u91cf\u7684\u503c<\/td>mutable int counter;<\/code><\/td><\/tr>
              inline<\/code><\/td>\u5185\u8054\u51fd\u6570\uff0c\u51cf\u5c11\u51fd\u6570\u8c03\u7528\u5f00\u9500<\/td>inline int sum(int a, int b);<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
              \u5408\u7406\u5730\u4f7f\u7528\u4fee\u9970\u7b26\u53ef\u4ee5\u63d0\u9ad8\u7a0b\u5e8f\u7684\u6027\u80fd\u3001\u53ef\u8bfb\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
              \u5728 C++ \u4e2d\uff0c\u4fee\u9970\u7b26\uff08Modifiers\uff09\u7528\u4e8e\u6539\u53d8\u6216\u4fee\u9970\u53d8\u91cf\u3001\u51fd\u6570\u6216\u7c7b\u7684\u884c\u4e3a\u548c\u5c5e\u6027\u3002\u4fee\u9970\u7b26\u901a\u8fc7\u589e\u52a0\u9644\u52a0\u7684\u7279\u6027 […]<\/p>\n","protected":false},"author":1,"featured_media":3248,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"class_list":["post-3247","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-c-"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3247","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=3247"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3247\/revisions"}],"predecessor-version":[{"id":3249,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3247\/revisions\/3249"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3248"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3247"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3247"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}