int转换为string形式

使用to_string函数。（C++11标准新增）

代码如下

#include <iostream>   // std::cout  
#include <string>     // std::string, std::to_string  
  
int main ()  
{  
  std::string pi = "pi is " + std::to_string(3.1415926);  
  std::string perfect = std::to_string(1+2+4+7+14) + " is a perfect number";  
  std::cout << pi << '\n';  
  std::cout << perfect << '\n';  
  return 0;  
}  

输出：

pi is 3.141593  
28 is a perfect number