{"id":3274,"date":"2025-03-29T15:07:42","date_gmt":"2025-03-29T07:07:42","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3274"},"modified":"2025-03-29T15:07:42","modified_gmt":"2025-03-29T07:07:42","slug":"c-%e6%8c%87%e9%92%88%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/29\/c-%e6%8c%87%e9%92%88%e8%af%a6%e8%a7%a3\/","title":{"rendered":"C++ \u6307\u9488\u8be6\u89e3"},"content":{"rendered":"\n

\u5728 C++ \u4e2d\uff0c\u6307\u9488\uff08Pointer\uff09<\/strong> \u662f\u53d8\u91cf\u7684\u5185\u5b58\u5730\u5740\uff0c\u6307\u9488\u53ef\u4ee5\u6307\u5411\u53d8\u91cf\u3001\u6570\u7ec4\u3001\u5b57\u7b26\u4e32\u3001\u51fd\u6570\u7b49\uff0c\u662f C++ \u5f3a\u5927\u4e14\u7075\u6d3b<\/strong> \u7684\u7279\u6027\u4e4b\u4e00\u3002\u672c\u6587\u5c06\u5168\u9762\u89e3\u6790 C++ \u6307\u9488\uff0c\u5305\u62ec \u5b9a\u4e49\u3001\u64cd\u4f5c\u3001\u6307\u9488\u8fd0\u7b97\u3001\u6307\u9488\u6570\u7ec4\u3001\u6307\u5411\u51fd\u6570\u7684\u6307\u9488\u3001\u6307\u9488\u4e0e new\/delete<\/code> \u7684\u7ed3\u5408<\/strong> \u7b49\u5185\u5bb9\u3002<\/p>\n\n\n\n

\n\n\n\n

1. \u6307\u9488\u7684\u57fa\u672c\u6982\u5ff5<\/strong><\/h2>\n\n\n\n

1.1 \u4ec0\u4e48\u662f\u6307\u9488\uff1f<\/strong><\/h3>\n\n\n\n

\u6307\u9488\u662f \u5b58\u50a8\u53d8\u91cf\u5730\u5740<\/strong> \u7684\u53d8\u91cf\uff0c\u5b83\u7684\u503c\u662f \u5185\u5b58\u5730\u5740<\/strong>\uff0c\u800c\u4e0d\u662f\u6570\u636e\u672c\u8eab\u3002<\/p>\n\n\n\n

int a = 10;  \/\/ \u666e\u901a\u53d8\u91cf\nint* p = &a; \/\/ p \u5b58\u50a8 a \u7684\u5730\u5740<\/code><\/pre>\n\n\n\n
\n
&\uff08\u53d6\u5730\u5740\u8fd0\u7b97\u7b26\uff09<\/strong>: \u83b7\u53d6\u53d8\u91cf\u7684\u5185\u5b58\u5730\u5740\u3002
*<\/code>\uff08\u89e3\u5f15\u7528\u8fd0\u7b97\u7b26\uff09<\/strong>: \u8bbf\u95ee\u6307\u9488\u6307\u5411\u7684\u53d8\u91cf\u503c\u3002<\/p>\n<\/blockquote>\n\n\n\n
\n\n\n\n
2. \u6307\u9488\u7684\u5b9a\u4e49\u4e0e\u4f7f\u7528<\/strong><\/h2>\n\n\n\n
2.1 \u5b9a\u4e49\u6307\u9488<\/strong><\/h3>\n\n\n\n
\u6570\u636e\u7c7b\u578b* \u6307\u9488\u53d8\u91cf\u540d;<\/code><\/pre>\n\n\n\n
\u793a\u4f8b\uff1a<\/p>\n\n\n\n
int a = 10;\nint* p = &a;  \/\/ p \u6307\u5411 a<\/code><\/pre>\n\n\n\n
\n
\u6ce8\u610f\uff1a<\/strong> int *p;<\/code> \u548c int* p;<\/code> \u90fd\u53ef\u4ee5\uff0c*<\/code> \u7ed1\u5b9a p<\/code>\uff0c\u8868\u793a\u5b83\u662f\u6307\u9488\u3002<\/p>\n<\/blockquote>\n\n\n\n
2.2 \u8bbf\u95ee\u6307\u9488\u6307\u5411\u7684\u503c<\/strong><\/h3>\n\n\n\n
#include <iostream>\nusing namespace std;\n\nint main() {\n    int a = 10;\n    int* p = &a;  \n    cout << \"\u53d8\u91cf a \u7684\u503c: \" << *p << endl;  \/\/ \u89e3\u5f15\u7528\n    return 0;\n}<\/code><\/pre>\n\n\n\n
\u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
\u53d8\u91cf a \u7684\u503c: 10<\/code><\/pre>\n\n\n\n
\n\n\n\n
3. \u6307\u9488\u8fd0\u7b97<\/strong><\/h2>\n\n\n\n
\u6307\u9488\u652f\u6301\u52a0\u6cd5\u3001\u51cf\u6cd5\u7b49\u8fd0\u7b97\uff0c\u5e38\u89c1\u6709\uff1a<\/p>\n\n\n\n
    \n
  • \u6307\u9488 + n\uff08p + n\uff09<\/strong>\uff1a\u6307\u9488\u5411\u540e\u79fb\u52a8 n<\/code> \u4e2a\u5355\u4f4d\uff08\u6309\u6570\u636e\u7c7b\u578b\u5927\u5c0f\uff09\u3002<\/li>\n\n\n\n
  • \u6307\u9488 – n\uff08p – n\uff09<\/strong>\uff1a\u6307\u9488\u5411\u524d\u79fb\u52a8 n<\/code> \u4e2a\u5355\u4f4d\u3002<\/li>\n\n\n\n
  • \u6307\u9488\u76f8\u51cf\uff08p2 – p1\uff09<\/strong>\uff1a\u8ba1\u7b97\u4e24\u4e2a\u6307\u9488\u95f4\u7684\u5143\u7d20\u4e2a\u6570\u3002<\/li>\n<\/ul>\n\n\n\n
    int arr[] = {10, 20, 30};\nint* p = arr;  \/\/ p \u6307\u5411 arr[0]\n\ncout << *(p + 1) << endl;  \/\/ 20\ncout << *(p + 2) << endl;  \/\/ 30<\/code><\/pre>\n\n\n\n
    \n
    \u6ce8\u610f<\/strong>\uff1a\u6307\u9488\u79fb\u52a8\u65f6\uff0c\u6b65\u957f \u4f9d\u8d56\u6570\u636e\u7c7b\u578b<\/strong>\uff08sizeof(type)<\/code>\uff09\u3002<\/p>\n<\/blockquote>\n\n\n\n
    \n\n\n\n
    4. \u6307\u9488\u4e0e\u6570\u7ec4<\/strong><\/h2>\n\n\n\n
    4.1 \u6307\u9488\u904d\u5386\u6570\u7ec4<\/strong><\/h3>\n\n\n\n
    int arr[] = {1, 2, 3, 4, 5};\nint* p = arr;  \/\/ \u6307\u9488\u6307\u5411\u6570\u7ec4\u9996\u5143\u7d20\nfor (int i = 0; i < 5; i++) {\n    cout << *(p + i) << \" \";\n}<\/code><\/pre>\n\n\n\n
    \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
    1 2 3 4 5<\/code><\/pre>\n\n\n\n
    \n
    \u6570\u7ec4\u540d\u672c\u8d28\u4e0a\u662f\u6307\u9488\u5e38\u91cf<\/strong>\uff0c\u5373 arr == &arr[0]<\/code>\u3002<\/p>\n<\/blockquote>\n\n\n\n
    4.2 \u6307\u9488\u8fd0\u7b97\u5728\u6570\u7ec4\u4e2d\u7684\u5e94\u7528<\/strong><\/h3>\n\n\n\n
    int arr[] = {10, 20, 30};\nint* p = arr;\n\ncout << p[0] << endl; \/\/ \u7b49\u4ef7\u4e8e *(p + 0)\ncout << p[1] << endl; \/\/ \u7b49\u4ef7\u4e8e *(p + 1)<\/code><\/pre>\n\n\n\n
    \n\n\n\n
    5. \u6307\u9488\u4e0e\u5b57\u7b26\u4e32<\/strong><\/h2>\n\n\n\n
    5.1 \u6307\u9488\u6307\u5411\u5b57\u7b26\u4e32<\/strong><\/h3>\n\n\n\n
    char str[] = \"Hello\";\nchar* p = str; \/\/ \u6307\u9488\u6307\u5411\u5b57\u7b26\u4e32\n\ncout << p << endl; \/\/ Hello<\/code><\/pre>\n\n\n\n
    5.2 \u5b57\u7b26\u4e32\u6307\u9488 vs. \u5b57\u7b26\u6570\u7ec4<\/strong><\/h3>\n\n\n\n
    char str1[] = \"Hello\";  \/\/ \u5b57\u7b26\u6570\u7ec4\nchar* str2 = \"Hello\";   \/\/ \u6307\u9488\uff08\u5b58\u50a8\u5b57\u7b26\u4e32\u7684\u5730\u5740\uff09<\/code><\/pre>\n\n\n\n
    \n
    str1<\/code> \u5141\u8bb8\u4fee\u6539\uff0c\u4f46 str2<\/code> \u4e0d\u80fd\u4fee\u6539<\/strong>\uff0c\u56e0\u4e3a\u5b83\u6307\u5411\u7684\u662f \u5b57\u7b26\u4e32\u5e38\u91cf<\/strong>\u3002<\/p>\n<\/blockquote>\n\n\n\n
    \n\n\n\n
    6. \u6307\u9488\u6570\u7ec4<\/strong><\/h2>\n\n\n\n
    \u6307\u9488\u6570\u7ec4<\/strong> \u662f\u4e00\u4e2a\u6570\u7ec4\uff0c\u6bcf\u4e2a\u5143\u7d20\u90fd\u662f\u6307\u9488\u3002<\/p>\n\n\n\n
    const char* strs[] = {\"C++\", \"Java\", \"Python\"};\n\ncout << strs[0] << endl;  \/\/ C++\ncout << strs[1] << endl;  \/\/ Java\ncout << strs[2] << endl;  \/\/ Python<\/code><\/pre>\n\n\n\n
    \n
    strs[i]<\/code> \u662f \u6307\u9488<\/strong>\uff0c\u6307\u5411\u5b57\u7b26\u4e32\u7684\u9996\u5730\u5740\u3002<\/p>\n<\/blockquote>\n\n\n\n
    \n\n\n\n
    7. \u6307\u9488\u7684\u6307\u9488\uff08\u591a\u7ea7\u6307\u9488\uff09<\/strong><\/h2>\n\n\n\n
    \u4e8c\u7ea7\u6307\u9488<\/strong> \u5b58\u50a8\u7684\u662f \u4e00\u7ea7\u6307\u9488\u7684\u5730\u5740<\/strong>\uff1a<\/p>\n\n\n\n
    int a = 10;\nint* p = &a;    \/\/ \u4e00\u7ea7\u6307\u9488\nint** pp = &p;  \/\/ \u4e8c\u7ea7\u6307\u9488<\/code><\/pre>\n\n\n\n
    \u8bbf\u95ee\u4e8c\u7ea7\u6307\u9488\u7684\u503c<\/strong><\/p>\n\n\n\n
    cout << **pp;  \/\/ 10<\/code><\/pre>\n\n\n\n
    \n
    **pp<\/code> \u5148\u89e3\u5f15\u7528 pp<\/code> \u5f97\u5230 p<\/code>\uff0c\u518d\u89e3\u5f15\u7528 p<\/code> \u5f97\u5230 a<\/code>\u3002<\/p>\n<\/blockquote>\n\n\n\n
    \n\n\n\n
    8. \u6307\u9488\u4e0e new<\/code> \/ delete<\/code>\uff08\u52a8\u6001\u5185\u5b58\u7ba1\u7406\uff09<\/strong><\/h2>\n\n\n\n
    8.1 \u52a8\u6001\u5206\u914d\u5355\u4e2a\u53d8\u91cf<\/strong><\/h3>\n\n\n\n
    int* p = new int(42); \/\/ \u7533\u8bf7\u4e00\u4e2a int\ncout << *p;  \/\/ 42\ndelete p;    \/\/ \u91ca\u653e\u5185\u5b58<\/code><\/pre>\n\n\n\n
    8.2 \u52a8\u6001\u6570\u7ec4<\/strong><\/h3>\n\n\n\n
    int* arr = new int[5]; \/\/ \u7533\u8bf7\u6570\u7ec4\nfor (int i = 0; i < 5; i++) {\n    arr[i] = i * 2;\n}\ndelete[] arr; \/\/ \u91ca\u653e\u6570\u7ec4<\/code><\/pre>\n\n\n\n
    \n
    delete<\/code> \u91ca\u653e\u5355\u4e2a\u53d8\u91cf\uff0cdelete[]<\/code> \u91ca\u653e\u6570\u7ec4\u3002<\/strong><\/p>\n<\/blockquote>\n\n\n\n
    \n\n\n\n
    9. \u51fd\u6570\u6307\u9488<\/strong><\/h2>\n\n\n\n
    \u51fd\u6570\u6307\u9488\u7528\u4e8e \u6307\u5411\u51fd\u6570<\/strong>\uff0c\u53ef\u7528\u4e8e \u56de\u8c03\u51fd\u6570<\/strong>\u3002<\/p>\n\n\n\n
    #include <iostream>\nusing namespace std;\n\nvoid sayHello() {\n    cout << \"Hello, world!\" << endl;\n}\n\n\/\/ \u5b9a\u4e49\u51fd\u6570\u6307\u9488\nvoid (*funcPtr)();\n\nint main() {\n    funcPtr = sayHello; \/\/ \u8d4b\u503c\n    funcPtr(); \/\/ \u8c03\u7528\u51fd\u6570\n}<\/code><\/pre>\n\n\n\n
    \u51fd\u6570\u6307\u9488\u4f20\u53c2<\/strong><\/p>\n\n\n\n
    void execute(void (*func)()) {\n    func();\n}\nexecute(sayHello); \/\/ \u4f20\u5165\u51fd\u6570\u6307\u9488<\/code><\/pre>\n\n\n\n
    \n\n\n\n
    10. nullptr<\/code> vs. NULL<\/code><\/strong><\/h2>\n\n\n\n
    \u5728 C++11 \u53ca\u4ee5\u4e0a\uff0c\u5efa\u8bae\u4f7f\u7528 nullptr<\/code> \u4ee3\u66ff NULL<\/code><\/strong>\uff1a<\/p>\n\n\n\n
    int* p = nullptr;<\/code><\/pre>\n\n\n\n
    \n
    nullptr<\/code> \u662f \u5f3a\u7c7b\u578b\u6307\u9488\u7a7a\u503c<\/strong>\uff0c\u6bd4 NULL<\/code> \u66f4\u5b89\u5168\u3002<\/p>\n<\/blockquote>\n\n\n\n
    \n\n\n\n
    11. \u603b\u7ed3<\/strong><\/h2>\n\n\n\n
      \n
    • \u6307\u9488\u5b58\u50a8\u53d8\u91cf\u7684\u5730\u5740<\/strong>\uff0c\u53ef\u7528\u4e8e\u6570\u7ec4\u3001\u5b57\u7b26\u4e32\u3001\u52a8\u6001\u5185\u5b58\u7b49\u3002<\/li>\n\n\n\n
    • *<\/code> \u89e3\u5f15\u7528\uff0c&<\/code> \u53d6\u5730\u5740<\/strong>\u3002<\/li>\n\n\n\n
    • \u6307\u9488\u8fd0\u7b97\u652f\u6301 +<\/code> -<\/code><\/strong>\uff0c\u79fb\u52a8\u65f6\u5355\u4f4d\u4e3a \u7c7b\u578b\u5927\u5c0f<\/strong>\u3002<\/li>\n\n\n\n
    • \u6570\u7ec4\u540d\u662f\u6307\u9488<\/strong>\uff0carr == &arr[0]<\/code>\u3002<\/li>\n\n\n\n
    • \u591a\u7ea7\u6307\u9488<\/strong>\uff1aint** p<\/code> \u5b58\u50a8 int*<\/code>\u3002<\/li>\n\n\n\n
    • \u52a8\u6001\u5185\u5b58<\/strong> \u9700\u8981 new<\/code> \u7533\u8bf7\uff0cdelete<\/code> \u91ca\u653e\u3002<\/li>\n\n\n\n
    • \u51fd\u6570\u6307\u9488<\/strong>\uff1a\u53ef\u7528\u4e8e \u56de\u8c03\u51fd\u6570<\/strong>\u3002<\/li>\n<\/ul>\n\n\n\n
      \u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
      \u5728 C++ \u4e2d\uff0c\u6307\u9488\uff08Pointer\uff09 \u662f\u53d8\u91cf\u7684\u5185\u5b58\u5730\u5740\uff0c\u6307\u9488\u53ef\u4ee5\u6307\u5411\u53d8\u91cf\u3001\u6570\u7ec4\u3001\u5b57\u7b26\u4e32\u3001\u51fd\u6570\u7b49\uff0c\u662f C++  […]<\/p>\n","protected":false},"author":1,"featured_media":3275,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"class_list":["post-3274","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\/3274","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=3274"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3274\/revisions"}],"predecessor-version":[{"id":3276,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3274\/revisions\/3276"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3275"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}