string对象与数值相互转换

 

#include<iostream>
#include<string>
#include<sstream>
using namespace std;

//c++方法：将数值转换为string
string convertToString(double x )
{
 ostringstream o ;
 if( o << x )
  return o.str();
 return "conversion error ";
}
//C++方法：将string转换为数值
double convertFromString( const string &s)
{
 istringstream i(s);
 double x ;
 if( i>> x)
  return x ;
 return 0.0;
}

int main(){

 char b[10];
 string a;
 sprintf( b , "%d" , 1975 );
 a = b;
 cout << a << endl;

 string cc = convertToString( 1976 );
 cout << cc <<endl;

 string dd = "2006";
 int p = convertFromString(dd) + 2;
 cout << p << endl;
 return 0;