Format double value : double Format « Data Type « C# / CSharp Tutorial

using System;  
class Example {  
  public static void Main() {  
    double s1 = 1231234.123412341234; 

    Console.WriteLine("{0:#.###}.", s1); 

2.28.double Format
2.28.1.Format double value
2.28.2.Display with 2 decimal places
2.28.3.Display with commas and 2 decimal places
2.28.4.Display using scientific notation
2.28.5.Scale the value by 1000
2.28.6.Display positive, negative, and zero values differently
2.28.7.Display a percentage
2.28.8.Double format specifiers:{0:F2}, {0:N5}, {0:e}, {0:r}, {0:p}, {0:X}, {0:D12}, {0:C}
2.28.9.Use ToString() to format doubles