{"id":194,"date":"2023-04-02T08:10:23","date_gmt":"2024-03-05T20:53:08","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/index.php\/2023\/11\/30\/%e5%a6%82%e4%bd%95%e5%9c%a8c%e4%b8%ad%e4%bd%bf%e7%94%a8%e5%ad%97%e7%ac%a6%e4%b8%b2%e7%9a%84find%e6%96%b9%e6%b3%95\/"},"modified":"2025-08-01T02:12:19","modified_gmt":"2025-07-31T18:12:19","slug":"%e5%a6%82%e4%bd%95%e5%9c%a8c%e4%b8%ad%e4%bd%bf%e7%94%a8%e5%ad%97%e7%ac%a6%e4%b8%b2%e7%9a%84find%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/%e5%a6%82%e4%bd%95%e5%9c%a8c%e4%b8%ad%e4%bd%bf%e7%94%a8%e5%ad%97%e7%ac%a6%e4%b8%b2%e7%9a%84find%e6%96%b9%e6%b3%95\/","title":{"rendered":"C++\u5b57\u7b26\u4e32\u67e5\u627e\uff1a\u6df1\u5165\u89e3\u6790find()\u65b9\u6cd5\u4e0e\u5b9e\u7528\u6280\u5de7"},"content":{"rendered":"

\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8\u5982\u4f55\u5728C++\u4e2d\u4f7f\u7528\u5b57\u7b26\u4e32\u7684find()<\/code>\u51fd\u6570\u3002<\/p>\n

\u5f53\u6211\u4eec\u9700\u8981\u68c0\u67e5\u4e00\u4e2a\u5b57\u7b26\u4e32\u662f\u5426\u5305\u542b\u53e6\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u65f6\uff0cstd::string::find()<\/code>\u65b9\u6cd5\u662f\u4e00\u4e2a\u975e\u5e38\u6709\u7528\u7684\u5de5\u5177\u3002\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u901a\u8fc7\u4e00\u4e9b\u5b9e\u4f8b\u6765\u8be6\u7ec6\u4e86\u89e3\u5b83\u7684\u7528\u6cd5\uff01<\/p>\n

\n

C++\u4e2d\u5b57\u7b26\u4e32find()\u7684\u8bed\u6cd5<\/h2>\n

find()<\/code>\u65b9\u6cd5\u662fC++\u6807\u51c6\u5e93\u4e2dstd::string<\/code>\u7c7b\u7684\u4e00\u4e2a\u6210\u5458\u51fd\u6570\u3002\u56e0\u6b64\uff0c\u5728\u4f7f\u7528\u5b83\u4e4b\u524d\uff0c\u6211\u4eec\u5fc5\u987b\u5305\u542b\u76f8\u5e94\u7684\u5934\u6587\u4ef6\uff08\u901a\u5e38\u662f<string><\/code>\uff09\u3002<\/p>\n

\u6211\u4eec\u5fc5\u987b\u5728\u4e00\u4e2astd::string<\/code>\u5bf9\u8c61\u4e0a\u8c03\u7528\u6b64\u51fd\u6570\uff0c\u5e76\u4f20\u5165\u53e6\u4e00\u4e2a\u5b57\u7b26\u4e32\u4f5c\u4e3a\u53c2\u6570\u3002find()<\/code>\u65b9\u6cd5\u4f1a\u68c0\u67e5\u7ed9\u5b9a\u7684\u5b50\u5b57\u7b26\u4e32\u662f\u5426\u5b58\u5728\u4e8e\u6211\u4eec\u7684\u4e3b\u5b57\u7b26\u4e32\u4e2d\u3002\u5982\u679c\u627e\u5230\uff0c\u5b83\u5c06\u8fd4\u56de\u5b50\u5b57\u7b26\u4e32\u9996\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e\uff08\u7d22\u5f15\uff09\uff0c\u7c7b\u578b\u4e3asize_t<\/code>\u3002\u5982\u679c\u5b50\u5b57\u7b26\u4e32\u4e0d\u5b58\u5728\uff0c\u5b83\u5c06\u8fd4\u56destd::string::npos<\/code>\uff08\u4e00\u4e2a\u8868\u793a\u201c\u672a\u627e\u5230\u201d\u7684\u7279\u6b8a\u503c\uff0c\u901a\u5e38\u662fsize_t<\/code>\u7684\u6700\u5927\u503c\uff09\u3002<\/p>\n

\u4ee5\u4e0b\u662ffind()<\/code>\u51fd\u6570\u7684\u4e00\u79cd\u5e38\u89c1\u5b9a\u4e49\u5f62\u5f0f\uff1a<\/p>\n

size_t find<\/span>(<\/span>const<\/span> std::<\/span>string&<\/span> my_string,<\/span> size_t pos =<\/span> 0<\/span>)<\/span>;<\/span>\r\n<\/code><\/pre>\n
\u5176\u4e2d\uff0cpos<\/code>\u662f\u4e00\u4e2a\u53ef\u9009\u53c2\u6570\uff0c\u5b83\u5b9a\u4e49\u4e86\u641c\u7d22\u7684\u8d77\u59cb\u4f4d\u7f6e\u3002\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0cpos<\/code>\u4e3a0<\/code>\uff0c\u8fd9\u610f\u5473\u7740\u641c\u7d22\u5c06\u4ece\u5b57\u7b26\u4e32\u7684\u5f00\u5934\u5f00\u59cb\uff0c\u9664\u975e\u60a8\u660e\u786e\u6307\u5b9a\u4e86\u5176\u4ed6\u8d77\u59cb\u4f4d\u7f6e\u3002<\/p>\n
\u8bf7\u6ce8\u610f\uff0cmy_string<\/code>\u53c2\u6570\u662f\u4ee5\u5e38\u91cf\u5f15\u7528\uff08const std::string&<\/code>\uff09\u7684\u65b9\u5f0f\u4f20\u9012\u7684\u3002\u7531\u4e8e\u6211\u4eec\u4e0d\u4f1a\u4fee\u6539\u4f20\u5165\u7684\u5b57\u7b26\u4e32\uff0c\u4f7f\u7528\u5f15\u7528\u53ef\u4ee5\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u5b57\u7b26\u4e32\u590d\u5236\uff0c\u4ece\u800c\u63d0\u9ad8\u6548\u7387\u3002<\/p>\n
\u6ce8\u610f\uff1a<\/strong> \u4eceC++20\u5f00\u59cb\uff0c\u8bb8\u591a\u6807\u51c6\u5e93\u65b9\u6cd5\u73b0\u5728\u652f\u6301constexpr<\/code>\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u4eec\u53ef\u4ee5\u5728\u7f16\u8bd1\u65f6\u6267\u884c\u3002\u60a8\u53ef\u4ee5\u67e5\u9605\u66f4\u591a\u5173\u4e8econstexpr<\/code>\u7684\u590d\u6742\u6027\u3002<\/p>\n
find()<\/code>\u51fd\u6570\u6709\u591a\u4e2a\u91cd\u8f7d\u7248\u672c\uff0c\u5176\u4e2d\u5927\u90e8\u5206\u6211\u4eec\u5728\u6b64\u5c06\u4e0d\u8be6\u7ec6\u5c55\u5f00\uff0c\u60a8\u53ef\u4ee5\u5728cppreference.com<\/a>\u4e0a\u67e5\u770b\u66f4\u591a\u4fe1\u606f\u3002\u76f8\u53cd\uff0c\u6211\u4eec\u5c06\u91cd\u70b9\u5173\u6ce8\u4e00\u4e2a\u6d89\u53ca\u5b50\u5b57\u7b26\u4e32\u957f\u5ea6\u7684\u7279\u5b9a\u91cd\u8f7d\uff1a<\/p>\n
size_t find<\/span>(<\/span> const<\/span> Char*<\/span> s,<\/span> size_type pos,<\/span> size_type count )<\/span>\r\n<\/code><\/pre>\n
\u8fd9\u4e2a\u7279\u5b9a\u7684\u91cd\u8f7d\u7528\u4e8e\u68c0\u67e5\u5b50\u5b57\u7b26\u4e32\u662f\u5426\u4f4d\u4e8e\u6211\u4eec\u7684\u5b57\u7b26\u4e32\u4e2d\uff0c\u4f46\u5b83\u8fd8\u5bf9\u5b50\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u6709\u9650\u5236\u3002\u5b83\u4f1a\u5339\u914d\u76f4\u5230\u6307\u5b9a\u7684\u5b57\u7b26\u6570\uff08\u7531count<\/code>\u53c2\u6570\u51b3\u5b9a\uff09\u3002<\/p>\n
\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u8fd9\u4e2a\u91cd\u8f7d\u4e0d\u80fd\u76f4\u63a5\u7528\u4e8estd::string<\/code>\u5bf9\u8c61\u3002\u8bf7\u7559\u610f\u539f\u578b\u4e2d\u7684const Char*<\/code>\uff0c\u8fd9\u8868\u660e\u5b83\u53ea\u80fd\u7528\u4e8eC\u98ce\u683c\u7684\u5b57\u7b26\u4e32\uff08\u5373\u5b57\u7b26\u6570\u7ec4\u6216\u5b57\u7b26\u4e32\u5b57\u9762\u91cf\uff09\u3002<\/p>\n
\u4f8b\u5982\uff0c\u5982\u679c\u6211\u4eec\u5c06\u5b50\u5b57\u7b26\u4e32\u201cHell\u201d\u4f20\u9012\u7ed9\u8fd9\u4e2a\u51fd\u6570\uff0c\u5e76\u9650\u5236\u5339\u914d\u957f\u5ea6\u4e3a3\uff1a<\/p>\n
std::<\/span>cout <<<\/span> \"Hello\"<\/span>.<\/span>find<\/span>(<\/span>\"Hell\"<\/span>,<\/span> 0<\/span>,<\/span> 3<\/span>)<\/span> <<<\/span> std::<\/span>endl;<\/span>\r\n<\/code><\/pre>\n
\u8fd9\u53ea\u4f1a\u5339\u914d\u201cHello\u201d\u4e2d\u7684\u524d3\u4e2a\u5b57\u7b26\uff08\u5373\u201cHel\u201d\uff09\u3002\u56e0\u6b64\uff0c\u4f5c\u4e3a\u8f93\u51fa\uff0c\u5b83\u5c06\u8fd4\u56de0\uff08\u56e0\u4e3a\u201cHel\u201d\u5728\u201cHello\u201d\u7684\u7d22\u5f150\u5904\uff09\u3002<\/p>\n
\u73b0\u5728\uff0c\u8ba9\u6211\u4eec\u901a\u8fc7\u4e00\u4e9b\u5177\u4f53\u7684\u4f8b\u5b50\u6765\u5de9\u56fa\u6211\u4eec\u6240\u5b66\u7684\u77e5\u8bc6\u3002<\/p>\n
\n
\u5728C++\u4e2d\u4f7f\u7528string.find()\u51fd\u6570<\/h2>\n
\u8fd9\u662f\u6587\u7ae0\u300a\u5982\u4f55\u5728C++\u4e2d\u4f7f\u7528\u5b57\u7b26\u4e32\u7684find()\u65b9\u6cd5\u300b\u7684\u7b2c2\u90e8\u5206\uff08\u51713\u90e8\u5206\uff09\u3002<\/p>\n
\u8ba9\u6211\u4eec\u6765\u770b\u4e00\u4e0bfind()<\/code>\u65b9\u6cd5\u7684\u9ed8\u8ba4\u8c03\u7528\uff0c\u5373\u5f53pos=0<\/code>\u65f6\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u5c06\u7b80\u5355\u5730\u4ece\u5b57\u7b26\u4e32\u7684\u5f00\u5934\u5f00\u59cb\u641c\u7d22\u6574\u4e2a\u5b50\u5b57\u7b26\u4e32\u3002<\/p>\n
#<\/span>include<\/span> <iostream><\/span><\/span>\r\n#<\/span>include<\/span> <string><\/span><\/span>\r\n\r\nint<\/span> main<\/span>(<\/span>)<\/span> {<\/span>\r\n    \/\/ \u521b\u5efa\u6211\u4eec\u7684\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string my_str<\/span>(<\/span>\"Hello from JournalDev\"<\/span>)<\/span>;<\/span>\r\n    \/\/ \u76ee\u6807\u641c\u7d22\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string target_string<\/span>(<\/span>\"JournalDev\"<\/span>)<\/span>;<\/span>\r\n\r\n    std::<\/span>cout <<<\/span> \"'\"<\/span> <<<\/span> target_string <<<\/span> \"' \u662f\u4e0d\u662f '\"<\/span> <<<\/span> my_str <<<\/span> \"' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\\n\"<\/span>;<\/span>\r\n    size_t substring_length =<\/span> my_str.<\/span>find<\/span>(<\/span>target_string)<\/span>;<\/span>\r\n    if<\/span> (<\/span>substring_length ==<\/span> 0<\/span>)<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5426\\n\"<\/span>;<\/span>\r\n    else<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = \"<\/span> <<<\/span> substring_length <<<\/span> std::<\/span>endl;<\/span>\r\n\r\n    return<\/span> 0<\/span>;<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u8f93\u51fa\uff1a<\/p>\n
'JournalDev' \u662f\u4e0d\u662f 'Hello from JournalDev' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\r\n\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = 11\r\n<\/code><\/pre>\n
\u4f60\u53ef\u4ee5\u770b\u5230\uff0c\u5728\u6211\u4eec\u7684\u539f\u59cb\u5b57\u7b26\u4e32\u4e2d\u786e\u5b9e\u5b58\u5728\u8fd9\u4e2a\u5b50\u5b57\u7b26\u4e32\uff01find()<\/code>\u65b9\u6cd5\u8fd4\u56de\u4e86\u5b50\u5b57\u7b26\u4e32\u5728\u4e3b\u5b57\u7b26\u4e32\u4e2d\u7684\u8d77\u59cb\u7d22\u5f15\u3002<\/p>\n
\u73b0\u5728\uff0c\u8ba9\u6211\u4eec\u5c1d\u8bd5\u4ece\u5b57\u7b26\u4e32\u7684\u7279\u5b9a\u4f4d\u7f6e\u5f00\u59cb\u641c\u7d22\u76f8\u540c\u7684\u5b50\u5b57\u7b26\u4e32\u3002<\/p>\n
#<\/span>include<\/span> <iostream><\/span><\/span>\r\n#<\/span>include<\/span> <string><\/span><\/span>\r\n\r\nint<\/span> main<\/span>(<\/span>)<\/span> {<\/span>\r\n    \/\/ \u521b\u5efa\u6211\u4eec\u7684\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string my_str<\/span>(<\/span>\"Hello from JournalDev\"<\/span>)<\/span>;<\/span>\r\n    \/\/ \u76ee\u6807\u641c\u7d22\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string target_string<\/span>(<\/span>\"JournalDev\"<\/span>)<\/span>;<\/span>\r\n\r\n    std::<\/span>cout <<<\/span> \"'\"<\/span> <<<\/span> target_string <<<\/span> \"' \u662f\u4e0d\u662f '\"<\/span> <<<\/span> my_str <<<\/span> \"' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\\n\"<\/span>;<\/span>\r\n    size_t substring_length =<\/span> my_str.<\/span>find<\/span>(<\/span>target_string,<\/span> 12<\/span>)<\/span>;<\/span> \/\/ \u4ece\u7d22\u5f1512\u5f00\u59cb\u641c\u7d22 (my_str[12]\u5904)<\/span>\r\n    if<\/span> (<\/span>substring_length ==<\/span> 0<\/span>)<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5426\\n\"<\/span>;<\/span>\r\n    else<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = \"<\/span> <<<\/span> substring_length <<<\/span> std::<\/span>endl;<\/span>\r\n\r\n    return<\/span> 0<\/span>;<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u8f93\u51fa\uff1a<\/p>\n
'JournalDev' \u662f\u4e0d\u662f 'Hello from JournalDev' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\r\n\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = 18446744073709551615\r\n<\/code><\/pre>\n
\u4e3a\u4ec0\u4e48\u6211\u4eec\u5f97\u5230\u4e86\u8fd9\u6837\u5947\u602a\u7684\u8f93\u51fa\uff1f\u56e0\u4e3a\u6211\u4eec\u4ece\u539f\u59cb\u5b57\u7b26\u4e32\u7684\u7b2c12\u4e2a\u7d22\u5f15\u5f00\u59cb\u641c\u7d22\uff0c\u800c\u76ee\u6807\u5b50\u5b57\u7b26\u4e32\"JournalDev\"<\/code>\u7684\u5b9e\u9645\u8d77\u59cb\u7d22\u5f15\u662f11\u3002\u4ece\u7d22\u5f1512\u5f00\u59cb\uff0c\u5b57\u7b26\u4e32\u7684\u5269\u4f59\u90e8\u5206\u4e0d\u8db3\u4ee5\u5305\u542b\u5b8c\u6574\u7684\"JournalDev\"<\/code>\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0cfind()<\/code>\u65b9\u6cd5\u4f1a\u8fd4\u56de\u4e00\u4e2a\u7279\u6b8a\u503c\uff0c\u8868\u793a\u672a\u627e\u5230\u5339\u914d\u9879\u3002\u8fd9\u4e2a\u7279\u6b8a\u503c\u901a\u5e38\u662fstd::string::npos<\/code>\uff0c\u5b83\u662f\u4e00\u4e2a\u975e\u5e38\u5927\u7684\u65e0\u7b26\u53f7\u6574\u6570\u503c\uff0c\u5728\u67d0\u4e9b\u7cfb\u7edf\u4e0a\u53ef\u80fd\u663e\u793a\u4e3a18446744073709551615<\/code>\u3002<\/p>\n
\u56e0\u6b64\uff0c\u5f53find()<\/code>\u65b9\u6cd5\u672a\u80fd\u627e\u5230\u5339\u914d\u9879\u65f6\uff0c\u5b83\u4f1a\u8fd4\u56destd::string::npos<\/code>\u3002\u6211\u4eec\u9700\u8981\u901a\u8fc7\u68c0\u67e5\u8fd4\u56de\u503c\u662f\u5426\u7b49\u4e8estd::string::npos<\/code>\u6765\u5224\u65ad\u662f\u5426\u627e\u5230\u4e86\u5b50\u5b57\u7b26\u4e32\u3002<\/p>\n
C++\u4e2d\u6709\u4e00\u4e2a\u7279\u6b8a\u7684\u5e38\u91cf\u53eb\u505astd::string::npos<\/code>\uff0c\u5b83\u8868\u793a\u201c\u672a\u627e\u5230\u201d\u6216\u201c\u5b57\u7b26\u4e32\u7684\u672b\u5c3e\u201d\u3002\u6211\u4eec\u53ef\u4ee5\u7528\u5b83\u6765\u68c0\u6d4bfind()<\/code>\u65b9\u6cd5\u662f\u5426\u627e\u5230\u4e86\u5339\u914d\u9879\u3002<\/p>\n
if<\/span> (<\/span>my_str.<\/span>find<\/span>(<\/span>target_str)<\/span> !=<\/span> std::<\/span>string::<\/span>npos)<\/span> {<\/span>\r\n    \/\/ \u627e\u5230\u4e86\u5339\u914d\u9879\uff01\u6211\u4eec\u4ecd\u5728\u539f\u59cb\u5b57\u7b26\u4e32\u8303\u56f4\u5185<\/span>\r\n}<\/span>\r\nelse<\/span> {<\/span>\r\n    \/\/ \u7cdf\u7cd5\uff01\u672a\u627e\u5230\u5339\u914d\u9879\u3002\u6253\u5370\u9519\u8bef\u4fe1\u606f\uff01<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u6709\u4e86\u8fd9\u4e2a\u6539\u8fdb\uff0c\u6211\u4eec\u7684\u4ee3\u7801\u73b0\u5728\u5c06\u53d8\u6210\u8fd9\u6837\uff1a<\/p>\n
#<\/span>include<\/span> <iostream><\/span><\/span>\r\n#<\/span>include<\/span> <string><\/span><\/span>\r\n\r\nint<\/span> main<\/span>(<\/span>)<\/span> {<\/span>\r\n    \/\/ \u521b\u5efa\u6211\u4eec\u7684\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string my_str<\/span>(<\/span>\"Hello from JournalDev\"<\/span>)<\/span>;<\/span>\r\n    \/\/ \u76ee\u6807\u641c\u7d22\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string target_string<\/span>(<\/span>\"JournalDev\"<\/span>)<\/span>;<\/span>\r\n\r\n    std::<\/span>cout <<<\/span> \"'\"<\/span> <<<\/span> target_string <<<\/span> \"' \u662f\u4e0d\u662f '\"<\/span> <<<\/span> my_str <<<\/span> \"' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\\n\"<\/span>;<\/span>\r\n    size_t substring_length;<\/span>\r\n    if<\/span> (<\/span>(<\/span>substring_length =<\/span> my_str.<\/span>find<\/span>(<\/span>target_string,<\/span> 12<\/span>)<\/span>)<\/span> !=<\/span> std::<\/span>string::<\/span>npos)<\/span> {<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = \"<\/span> <<<\/span> substring_length <<<\/span> std::<\/span>endl;<\/span>\r\n    }<\/span>\r\n    else<\/span> {<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5426\\n\"<\/span>;<\/span>\r\n    }<\/span>\r\n\r\n    return<\/span> 0<\/span>;<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u8f93\u51fa\uff1a<\/p>\n
'JournalDev' \u662f\u4e0d\u662f 'Hello from JournalDev' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\r\n\u5426\r\n<\/code><\/pre>\n
\u73b0\u5728\uff0c\u6211\u4eec\u5f97\u5230\u4e86\u6211\u4eec\u671f\u671b\u7684\u8f93\u51fa\uff0c\u56e0\u4e3a\u6211\u4eec\u4ece\u7d22\u5f1512\u5f00\u59cb\u641c\u7d22\uff0c\u800c\u4ece\u8be5\u4f4d\u7f6e\u5f00\u59cb\u65e0\u6cd5\u627e\u5230\u5b8c\u6574\u7684\u201cJournalDev\u201d\u5b50\u5b57\u7b26\u4e32\u3002<\/p>\n
\u8ba9\u6211\u4eec\u4f7f\u7528\u8fd9\u4e2a\u68c0\u67e5\u6765\u5c55\u793afind()<\/code>\u7684\u53e6\u4e00\u79cd\u91cd\u8f7d\u5f62\u5f0f\uff0c\u5b83\u63a5\u53d7\u4e00\u4e2a\u8ba1\u6570\u53c2\u6570\u3002\u8bf7\u8bb0\u4f4f\uff0c\u6211\u4eec\u4e0d\u80fd\u76f4\u63a5\u5bf9std::string<\/code>\u5bf9\u8c61\u4f7f\u7528\u8fd9\u79cd\u5f62\u5f0f\uff0c\u5b83\u901a\u5e38\u7528\u4e8eC\u98ce\u683c\u7684\u5b57\u7b26\u4e32\uff08const char*<\/code>\uff09\u3002<\/p>\n
#<\/span>include<\/span> <iostream><\/span><\/span>\r\n#<\/span>include<\/span> <string><\/span><\/span>\r\n\r\nint<\/span> main<\/span>(<\/span>)<\/span> {<\/span>\r\n    \/\/ \u521b\u5efa\u6211\u4eec\u7684\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string my_str<\/span>(<\/span>\"Hello from JournalDev\"<\/span>)<\/span>;<\/span>\r\n    \/\/ \u76ee\u6807\u641c\u7d22\u5b57\u7b26\u4e32<\/span>\r\n    std::<\/span>string target_string<\/span>(<\/span>\"Journ_kkfffsfsfskkk\"<\/span>)<\/span>;<\/span>\r\n\r\n    std::<\/span>cout <<<\/span> \"'\"<\/span> <<<\/span> target_string <<<\/span> \"' \u662f\u4e0d\u662f '\"<\/span> <<<\/span> my_str <<<\/span> \"' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\\n\"<\/span>;<\/span>\r\n    size_t substring_length;<\/span>\r\n    \/\/ \u4f7f\u7528\u8ba1\u6570\u53c2\u6570\uff0c\u53ea\u5339\u914d\u524d5\u4e2a\u5b57\u7b26<\/span>\r\n    \/\/ \u6ce8\u610f\uff1a\u8fd9\u79cd\u5f62\u5f0f\u901a\u5e38\u7528\u4e8e const char* \u5b57\u7b26\u4e32<\/span>\r\n    if<\/span> (<\/span>(<\/span>substring_length =<\/span> my_str.<\/span>find<\/span>(<\/span>\"Journ_kkfffsfsfskkk\"<\/span>,<\/span> 0<\/span>,<\/span> 5<\/span>)<\/span>)<\/span> !=<\/span> std::<\/span>string::<\/span>npos)<\/span> {<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = \"<\/span> <<<\/span> substring_length <<<\/span> std::<\/span>endl;<\/span>\r\n    }<\/span>\r\n    else<\/span> {<\/span>\r\n        std::<\/span>cout <<<\/span> \"\u5426\\n\"<\/span>;<\/span>\r\n    }<\/span>\r\n\r\n    return<\/span> 0<\/span>;<\/span>\r\n}<\/span>\r\n<\/code><\/pre>\n
\u8f93\u51fa\uff1a<\/p>\n
'Journ_kkfffsfsfskkk' \u662f\u4e0d\u662f 'Hello from JournalDev' \u7684\u5b50\u5b57\u7b26\u4e32\uff1f\r\n\u5339\u914d\u5b50\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u7d22\u5f15 = 11\r\n<\/code><\/pre>\n
\u8bf7\u6ce8\u610f\uff0c\u6211\u4eec\u5df2\u7ecf\u6539\u53d8\u4e86\u76ee\u6807\u5b57\u7b26\u4e32\u3002\u5c3d\u7ba1target_string<\/code>\u5f88\u957f\uff0c\u4f46\u7531\u4e8e\u6211\u4eec\u8bbe\u7f6e\u4e86\u8ba1\u6570\u9650\u5236\u4e3a5\uff0cfind()<\/code>\u65b9\u6cd5\u53ea\u4f1a\u5c1d\u8bd5\u5339\u914d\"Journ\"<\/code>\u8fd9\u524d5\u4e2a\u5b57\u7b26\u3002\u5bf9\u4e8efind()<\/code>\u6765\u8bf4\uff0c\u8fd9\u5df2\u7ecf\u8db3\u591f\u4e86\uff01<\/p>\n
\u56e0\u6b64\uff0c\u5b83\u4f1a\u5ffd\u7565\u76ee\u6807\u5b50\u5b57\u7b26\u4e32\u7684\u5176\u4f59\u90e8\u5206\uff0c\u5e76\u7ee7\u7eed\u5728\u539f\u59cb\u5b57\u7b26\u4e32\u4e2d\u8fdb\u884c\u5339\u914d\uff0c\u76f4\u5230\u627e\u5230\u7b26\u5408\u6761\u4ef6\u7684\u5b50\u5e8f\u5217\u3002\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u6211\u4eec\u4ecd\u7136\u5f97\u523011\u4f5c\u4e3a\u8d77\u59cb\u7d22\u5f15\uff0c\u56e0\u4e3a\u5b83\u662f\u627e\u5230\u201cJourn\u201d\u5b50\u5b57\u7b26\u4e32\u5339\u914d\u7684\u4f4d\u7f6e\u3002<\/p>\n
\n
\u7ed3\u8bba<\/h2>\n
\u5e0c\u671b\u901a\u8fc7\u8fd9\u4e9b\u793a\u4f8b\uff0c\u60a8\u5df2\u7ecf\u6e05\u695a\u5730\u4e86\u89e3\u4e86\u5982\u4f55\u5728 C++ \u4e2d\u8f7b\u677e\u4f7f\u7528 string.find()<\/code> \u65b9\u6cd5\u3002\u5982\u679c\u60a8\u6709\u4efb\u4f55\u7591\u95ee\uff0c\u8bf7\u5728\u4e0b\u65b9\u7684\u8bc4\u8bba\u533a\u63d0\u51fa\uff01<\/p>\n
\u6b64\u5916\uff0c\u5728\u6211\u4eec\u7684\u6559\u7a0b\u90e8\u5206\u8fd8\u6709\u5176\u4ed6\u5173\u4e8e C++ \u7684\u7cbe\u5f69\u6587\u7ae0\uff0c\u6b22\u8fce\u67e5\u9605\uff01<\/p>\n
\n
\u53c2\u8003\u6587\u732e<\/h2>\n