C++代码

#include<stdlib.h> atoi字符串转int，atof 字符串转float

 double，int 转字符串 double no=1.2   string str; stringstream ss;ss<<no; ss>>str;   ＃i nclude <sstream> 

截取字符串

    string s("12345asdf");
     string a = s.substr(0,5);     //获得字符串s中从第0位开始的长度为5的字符串
     std::cout<<a<<endl;