C++11中int,float,double與string的轉化，floatdouble

C++11中int,float,double與string的轉化，floatdouble

在C++11中可以使用std::to_string()函數將數值轉換為string格式，十分方便。

以下部分來選自cplusplus.com。

std::to_string

string to_string (int val);
string to_string (long val);
string to_string (long long val);
string to_string (unsigned val);
string to_string (unsigned long val);
string to_string (unsigned long long val);
string to_string (float val);
string to_string (double val);
string to_string (long double val);

Returns a string with the representation of val.

示例

 1 // to_string example
 2 #include <iostream>   // std::cout
 3 #include <string>     // std::string, std::to_string
 4 
 5 int main ()
 6 {
 7   std::string pi = "pi is " + std::to_string(3.1415926);
 8   std::string perfect = std::to_string(1+2+4+7+14) + " is a perfect number";
 9   std::cout << pi << '\n';
10   std::cout << perfect << '\n';
11   return 0;
12 }

輸出

pi is 3.141593

28 is a perfect numbe

參考資料

[1]http://www.cplusplus.com/reference/string/to_string/