C++ 遇到的问题小结

 1                           int id2;
 2                           std::string label2;
 3                           std::string line;
 4 
 5                           while(getline(file, line)){
 6                             label2 = line.substr(5, line.size());
 7                             id2 = line.substr(1,4);
 8 
 9                             if (id2 == xxx)
10                                 break;
11                         }

1                         while(getline(file, line)){
2                             label2 = line.substr(5, line.size());
3                             id2 = atoi((line.substr(1,4)).c_str());
4 
5                             if (id2 == xxx)
6                                 break;
7                         ｝