Format double to a easy-parse format with Round-trip ("R") Format Specifier in CSharp

using System;/*  ww w . ja  v a  2s.co  m*/
using System.Globalization;
public class MainClass {     
   static void Main()
   {
        double value;
        
        value = Math.PI;
        Console.WriteLine(value.ToString("r"));
        // Displays 3.1415926535897931
        Console.WriteLine(value.ToString("r", 
                          CultureInfo.CreateSpecificCulture("fr-FR")));
        // Displays 3,1415926535897931 
        value = 1.623e-21;
        Console.WriteLine(value.ToString("r"));
        // Displays 1.623E-21
  }
}