{"id":3238,"date":"2025-03-27T23:52:35","date_gmt":"2025-03-27T15:52:35","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3238"},"modified":"2025-03-27T23:52:35","modified_gmt":"2025-03-27T15:52:35","slug":"c-%e5%8f%98%e9%87%8f%e7%b1%bb%e5%9e%8b%ef%bc%88variables-in-c%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/27\/c-%e5%8f%98%e9%87%8f%e7%b1%bb%e5%9e%8b%ef%bc%88variables-in-c%ef%bc%89\/","title":{"rendered":"C++ \u53d8\u91cf\u7c7b\u578b\uff08Variables in C++\uff09"},"content":{"rendered":"\n

\u53d8\u91cf\u662f\u7a0b\u5e8f\u4e2d\u7528\u4e8e\u5b58\u50a8\u6570\u636e\u7684\u547d\u540d\u5185\u5b58\u7a7a\u95f4<\/strong>\u3002C++ \u53d8\u91cf\u6709\u4e0d\u540c\u7684\u7c7b\u578b\uff0c\u4e3b\u8981\u5305\u62ec\u5c40\u90e8\u53d8\u91cf\u3001\u5168\u5c40\u53d8\u91cf\u3001\u9759\u6001\u53d8\u91cf\u3001\u5e38\u91cf\u53d8\u91cf<\/strong>\u7b49\u3002<\/p>\n\n\n\n

\n\n\n\n

1. \u53d8\u91cf\u7684\u58f0\u660e\u548c\u521d\u59cb\u5316<\/strong><\/h2>\n\n\n\n

1.1 \u53d8\u91cf\u58f0\u660e<\/strong><\/h3>\n\n\n\n

\u5728 C++ \u4e2d\uff0c\u53d8\u91cf\u5728\u4f7f\u7528\u524d\u5fc5\u987b\u5148\u58f0\u660e\uff1a<\/p>\n\n\n\n

\u6570\u636e\u7c7b\u578b \u53d8\u91cf\u540d;<\/code><\/pre>\n\n\n\n
\u793a\u4f8b\uff1a<\/p>\n\n\n\n
int age;      \/\/ \u58f0\u660e\u4e00\u4e2a\u6574\u578b\u53d8\u91cf\ndouble pi;    \/\/ \u58f0\u660e\u4e00\u4e2a\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u6570\nchar grade;   \/\/ \u58f0\u660e\u4e00\u4e2a\u5b57\u7b26<\/code><\/pre>\n\n\n\n
1.2 \u53d8\u91cf\u521d\u59cb\u5316<\/strong><\/h3>\n\n\n\n
\u5728\u58f0\u660e\u53d8\u91cf\u7684\u540c\u65f6\uff0c\u53ef\u4ee5\u5bf9\u5176\u8fdb\u884c\u521d\u59cb\u5316\uff1a<\/p>\n\n\n\n
int age = 25;\ndouble pi = 3.14159;\nchar grade = 'A';<\/code><\/pre>\n\n\n\n
1.3 \u591a\u4e2a\u53d8\u91cf\u540c\u65f6\u58f0\u660e<\/strong><\/h3>\n\n\n\n
int a = 10, b = 20, c = 30;<\/code><\/pre>\n\n\n\n
\n\n\n\n
2. C++ \u53d8\u91cf\u7c7b\u578b<\/strong><\/h2>\n\n\n\n
2.1 \u5c40\u90e8\u53d8\u91cf\uff08Local Variables\uff09<\/strong><\/h3>\n\n\n\n
\u5c40\u90e8\u53d8\u91cf\u5728\u51fd\u6570\u6216\u4ee3\u7801\u5757<\/strong>\u4e2d\u58f0\u660e\uff0c\u53ea\u80fd\u5728\u8be5\u8303\u56f4\u5185\u8bbf\u95ee\u3002<\/p>\n\n\n\n
#include <iostream>\nusing namespace std;\n\nvoid display() {\n    int x = 10;  \/\/ \u5c40\u90e8\u53d8\u91cf\uff0c\u4ec5\u5728 display() \u5185\u6709\u6548\n    cout << \"x = \" << x << endl;\n}\n\nint main() {\n    display();\n    \/\/ cout << x; \/\/ \u274c \u9519\u8bef\uff1ax \u5728 main() \u4e2d\u4e0d\u53ef\u8bbf\u95ee\n    return 0;\n}<\/code><\/pre>\n\n\n\n
\u7279\u70b9<\/strong>\uff1a<\/p>\n\n\n\n
    \n
  • \u53ea\u5728\u5b9a\u4e49\u5b83\u7684\u4ee3\u7801\u5757<\/strong>\u4e2d\u53ef\u7528\u3002<\/li>\n\n\n\n
  • \u53d8\u91cf\u4f1a\u5728\u4ee3\u7801\u5757\u7ed3\u675f\u65f6\u9500\u6bc1<\/strong>\uff0c\u91ca\u653e\u5185\u5b58\u3002<\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n
    2.2 \u5168\u5c40\u53d8\u91cf\uff08Global Variables\uff09<\/strong><\/h3>\n\n\n\n
    \u5168\u5c40\u53d8\u91cf\u5728\u51fd\u6570\u5916\u90e8<\/strong>\u58f0\u660e\uff0c\u4f5c\u7528\u57df\u4e3a\u6574\u4e2a\u7a0b\u5e8f\u3002<\/p>\n\n\n\n
    #include <iostream>\nusing namespace std;\n\nint g = 100; \/\/ \u5168\u5c40\u53d8\u91cf\n\nvoid display() {\n    cout << \"g = \" << g << endl;\n}\n\nint main() {\n    display();\n    g = 200;  \/\/ \u53ef\u5728\u4efb\u4f55\u51fd\u6570\u4e2d\u8bbf\u95ee\u548c\u4fee\u6539\n    cout << \"g = \" << g << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
    \u7279\u70b9<\/strong>\uff1a<\/p>\n\n\n\n
      \n
    • \u4f5c\u7528\u57df\u8986\u76d6\u6574\u4e2a\u7a0b\u5e8f<\/strong>\u3002<\/li>\n\n\n\n
    • \u751f\u547d\u5468\u671f\u8d2f\u7a7f\u6574\u4e2a\u7a0b\u5e8f\u8fd0\u884c<\/strong>\u3002<\/li>\n\n\n\n
    • \u53ef\u80fd\u5bfc\u81f4\u547d\u540d\u51b2\u7a81<\/strong>\uff0c\u6240\u4ee5\u5e94\u5c3d\u91cf\u51cf\u5c11\u4f7f\u7528\u3002<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      2.3 \u9759\u6001\u53d8\u91cf\uff08Static Variables\uff09<\/strong><\/h3>\n\n\n\n
      \u9759\u6001\u53d8\u91cf\u4f7f\u7528 static<\/code> \u5173\u952e\u5b57\u58f0\u660e\uff0c\u5b83\u5728\u7a0b\u5e8f\u8fd0\u884c\u671f\u95f4<\/strong>\u53ea\u521d\u59cb\u5316\u4e00\u6b21\uff0c\u5e76\u4fdd\u6301\u5176\u503c\u4e0d\u53d8\u3002<\/p>\n\n\n\n
      #include <iostream>\nusing namespace std;\n\nvoid counter() {\n    static int count = 0; \/\/ \u53ea\u521d\u59cb\u5316\u4e00\u6b21\n    count++;\n    cout << \"count = \" << count << endl;\n}\n\nint main() {\n    counter();\n    counter();\n    counter();\n    return 0;\n}<\/code><\/pre>\n\n\n\n
      \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
      count = 1\ncount = 2\ncount = 3<\/code><\/pre>\n\n\n\n
      \u7279\u70b9<\/strong>\uff1a<\/p>\n\n\n\n
        \n
      • \u5c40\u90e8\u9759\u6001\u53d8\u91cf<\/strong>\u53ea\u5728\u7b2c\u4e00\u6b21\u8c03\u7528\u65f6\u521d\u59cb\u5316<\/strong>\uff0c\u540e\u7eed\u8c03\u7528\u4fdd\u6301\u539f\u503c\u3002<\/li>\n\n\n\n
      • \u5168\u5c40\u9759\u6001\u53d8\u91cf<\/strong>\u4f5c\u7528\u57df\u4ec5\u9650\u5f53\u524d\u6587\u4ef6<\/strong>\uff0c\u4e0d\u4f1a\u88ab\u5916\u90e8\u6587\u4ef6\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n
        2.4 \u5e38\u91cf\u53d8\u91cf\uff08Constant Variables\uff09<\/strong><\/h3>\n\n\n\n
        \u5e38\u91cf\u53d8\u91cf\u4f7f\u7528 const<\/code> \u5173\u952e\u5b57\u58f0\u660e\uff0c\u503c\u4e0d\u80fd\u88ab\u4fee\u6539<\/strong>\u3002<\/p>\n\n\n\n
        #include <iostream>\nusing namespace std;\n\nint main() {\n    const double PI = 3.14159;\n    \/\/ PI = 3.14; \/\/ \u274c \u9519\u8bef\uff1a\u5e38\u91cf\u4e0d\u80fd\u4fee\u6539\n    cout << \"PI = \" << PI << endl;\n    return 0;\n}<\/code><\/pre>\n\n\n\n
        \u7279\u70b9<\/strong>\uff1a<\/p>\n\n\n\n
          \n
        • \u53ea\u80fd\u521d\u59cb\u5316\u4e00\u6b21<\/strong>\uff0c\u540e\u7eed\u4e0d\u53ef\u66f4\u6539\u3002<\/li>\n\n\n\n
        • \u53ef\u4ee5\u7528\u4e8e\u6570\u7ec4\u5927\u5c0f<\/strong>\u3001\u6570\u5b66\u5e38\u91cf<\/strong>\u7b49\u573a\u666f\u3002<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n
          2.5 \u53d8\u91cf\u4f5c\u7528\u57df<\/strong><\/h3>\n\n\n\n
          \u53d8\u91cf\u7684\u4f5c\u7528\u57df\u51b3\u5b9a\u4e86\u5b83\u5728\u54ea\u4e9b\u5730\u65b9\u53ef\u4ee5\u88ab\u8bbf\u95ee\uff1a<\/p>\n\n\n\n
          \u53d8\u91cf\u7c7b\u578b<\/th>\u4f5c\u7528\u8303\u56f4<\/th>\u751f\u547d\u5468\u671f<\/th><\/tr><\/thead>
          \u5c40\u90e8\u53d8\u91cf<\/strong><\/td>\u4ee3\u7801\u5757\uff08\u51fd\u6570\u5185\uff09<\/td>\u4ee3\u7801\u5757\u7ed3\u675f\u65f6\u9500\u6bc1<\/td><\/tr>
          \u5168\u5c40\u53d8\u91cf<\/strong><\/td>\u6574\u4e2a\u7a0b\u5e8f<\/td>\u7a0b\u5e8f\u8fd0\u884c\u671f\u95f4<\/td><\/tr>
          \u9759\u6001\u53d8\u91cf<\/strong><\/td>\u4ee3\u7801\u5757\u5185<\/td>\u4ec5\u521d\u59cb\u5316\u4e00\u6b21\uff0c\u7a0b\u5e8f\u7ed3\u675f\u65f6\u9500\u6bc1<\/td><\/tr>
          \u5e38\u91cf\u53d8\u91cf<\/strong><\/td>\u4ee3\u7801\u5757\u6216\u5168\u5c40<\/td>\u4ec5\u521d\u59cb\u5316\u4e00\u6b21\uff0c\u4e0d\u80fd\u4fee\u6539<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          \n\n\n\n
          3. \u53d8\u91cf\u7c7b\u578b\u793a\u4f8b\u603b\u7ed3<\/strong><\/h2>\n\n\n\n
          #include <iostream>\nusing namespace std;\n\n\/\/ \u5168\u5c40\u53d8\u91cf\nint globalVar = 50;\n\nvoid testStatic() {\n    static int count = 0; \/\/ \u9759\u6001\u53d8\u91cf\n    count++;\n    cout << \"Static count = \" << count << endl;\n}\n\nint main() {\n    int localVar = 10;    \/\/ \u5c40\u90e8\u53d8\u91cf\n    const double pi = 3.14; \/\/ \u5e38\u91cf\u53d8\u91cf\n\n    cout << \"Local variable: \" << localVar << endl;\n    cout << \"Global variable: \" << globalVar << endl;\n    cout << \"Constant PI: \" << pi << endl;\n\n    testStatic();\n    testStatic();\n    testStatic();\n\n    return 0;\n}<\/code><\/pre>\n\n\n\n
          \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
          Local variable: 10\nGlobal variable: 50\nConstant PI: 3.14\nStatic count = 1\nStatic count = 2\nStatic count = 3<\/code><\/pre>\n\n\n\n
          \n\n\n\n
          4. \u53d8\u91cf\u547d\u540d\u89c4\u5219<\/strong><\/h2>\n\n\n\n
          C++ \u53d8\u91cf\u547d\u540d\u9700\u8981\u9075\u5faa\u4ee5\u4e0b\u89c4\u5219\uff1a
          \u2705 \u4ee5\u5b57\u6bcd\u6216 _<\/code>\uff08\u4e0b\u5212\u7ebf\uff09\u5f00\u5934
          \u2705 \u53ea\u80fd\u5305\u542b \u5b57\u6bcd\u3001\u6570\u5b57\u3001\u4e0b\u5212\u7ebf<\/strong>
          \u2705 \u4e0d\u80fd\u4f7f\u7528 C++ \u5173\u952e\u5b57<\/strong>\uff08\u5982 int, float, return<\/code> \u7b49\uff09
          \u2705 \u533a\u5206\u5927\u5c0f\u5199<\/strong>\uff08var<\/code> \u548c Var<\/code> \u662f\u4e0d\u540c\u53d8\u91cf\uff09
          \u2705 \u63a8\u8350\u4f7f\u7528 \u6709\u610f\u4e49\u7684\u53d8\u91cf\u540d<\/strong>\uff0c\u907f\u514d a, b, c<\/code> \u4e4b\u7c7b\u7684\u65e0\u610f\u4e49\u53d8\u91cf\u540d<\/p>\n\n\n\n
          \n\n\n\n
          5. \u603b\u7ed3<\/strong><\/h2>\n\n\n\n
          \u53d8\u91cf\u7c7b\u578b<\/th>\u5173\u952e\u5b57<\/th>\u4f5c\u7528\u8303\u56f4<\/th>\u751f\u547d\u5468\u671f<\/th>\u5907\u6ce8<\/th><\/tr><\/thead>
          \u5c40\u90e8\u53d8\u91cf<\/strong><\/td>\u65e0<\/td>\u4ee3\u7801\u5757\u5185<\/td>\u4ee3\u7801\u5757\u7ed3\u675f\u65f6\u9500\u6bc1<\/td>\u53ea\u5728\u5f53\u524d\u4f5c\u7528\u57df\u6709\u6548<\/td><\/tr>
          \u5168\u5c40\u53d8\u91cf<\/strong><\/td>\u65e0<\/td>\u6574\u4e2a\u7a0b\u5e8f<\/td>\u7a0b\u5e8f\u8fd0\u884c\u671f\u95f4<\/td>\u5360\u7528\u6574\u4e2a\u7a0b\u5e8f\u7684\u5185\u5b58<\/td><\/tr>
          \u9759\u6001\u53d8\u91cf<\/strong><\/td>static<\/code><\/td>\u4ee3\u7801\u5757\u5185<\/td>\u7a0b\u5e8f\u8fd0\u884c\u671f\u95f4<\/td>\u4ec5\u521d\u59cb\u5316\u4e00\u6b21\uff0c\u503c\u4fdd\u7559<\/td><\/tr>
          \u5e38\u91cf\u53d8\u91cf<\/strong><\/td>const<\/code><\/td>\u4ee3\u7801\u5757\u6216\u5168\u5c40<\/td>\u4ec5\u521d\u59cb\u5316\u4e00\u6b21<\/td>\u503c\u4e0d\u53ef\u66f4\u6539<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          \ud83d\ude80 \u6700\u4f73\u5b9e\u8df5<\/strong>\uff1a<\/p>\n\n\n\n
            \n
          • \u5c40\u90e8\u53d8\u91cf\u4f18\u5148<\/strong>\uff0c\u51cf\u5c11\u5168\u5c40\u53d8\u91cf\u4f7f\u7528\uff0c\u907f\u514d\u547d\u540d\u51b2\u7a81\u3002<\/li>\n\n\n\n
          • \u9759\u6001\u53d8\u91cf<\/strong>\u9002\u7528\u4e8e\u9700\u8981\u8bb0\u5fc6\u72b6\u6001<\/strong>\u7684\u573a\u666f\uff0c\u5982\u8ba1\u6570\u5668\u3002<\/li>\n\n\n\n
          • \u5e38\u91cf\u53d8\u91cf<\/strong>\u7528\u4e8e\u5b58\u50a8\u4e0d\u4f1a\u66f4\u6539\u7684\u503c\uff0c\u63d0\u9ad8\u4ee3\u7801\u5b89\u5168\u6027\u548c\u53ef\u8bfb\u6027\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
            \u53d8\u91cf\u662f\u7a0b\u5e8f\u4e2d\u7528\u4e8e\u5b58\u50a8\u6570\u636e\u7684\u547d\u540d\u5185\u5b58\u7a7a\u95f4\u3002C++ \u53d8\u91cf\u6709\u4e0d\u540c\u7684\u7c7b\u578b\uff0c\u4e3b\u8981\u5305\u62ec\u5c40\u90e8\u53d8\u91cf\u3001\u5168\u5c40\u53d8\u91cf\u3001\u9759\u6001\u53d8\u91cf\u3001\u5e38\u91cf\u53d8 […]<\/p>\n","protected":false},"author":1,"featured_media":3239,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"class_list":["post-3238","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\/3238","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=3238"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3238\/revisions"}],"predecessor-version":[{"id":3240,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3238\/revisions\/3240"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3239"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3238"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3238"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3238"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}