[C++] string to int, int to string, string to double, double to string

Convert.h

#ifndef CONVERT_H_ #define CONVERT_H_ #include <sstream> #include <string> using namespace std; class Convert{ public:     static int str2int(const string &str);     static string int2str(const int n);     static double str2double(const string &str);     static string double2str(const double n); }; #endif /*CONVERT_H_*/

Convert.cpp

#include "Convert.h" int Convert::str2int (const string &str) {     int n;     stringstream ss(str);        ss >> n;            return n; };    string Convert::int2str (const int n) {     stringstream ss;     ss << n;     return ss.str(); } double Convert::str2double(const string &str){     double n;     stringstream ss(str);        ss >> n;            return n; } string Convert::double2str(const double n){     stringstream ss;     ss << n;     return ss.str(); }