字符串与数字互相转换

 #include <sstream>  //include this to use string streams
 #include <string> 

int main()
{    
    int number = 1234;

    std::ostringstream ostr; //output string stream
    ostr << number; //use the string stream just like cout,
    //except the stream prints not to stdout but to a string.

    std::string theNumberString = ostr.str(); //the str() function of the stream 
    //returns the string.

    //now  theNumberString is "1234"  
}

#include <sstream>
#include <string>
int main()
{
   std::string inputString = "1234 12.3 44";
   std::istringstream istr(inputString);
   int i1, i2;
   float f;
   istr >> i1 >> f >> i2;
   //i1 is 1234, f is 12.3, i2 is 44  
}