Csharp/CSharp Tutorial/Data Type/double Format

Display a percentage

using System;  
class MainClass {  
  public static void Main() {  
    double num = 0.17;     
    Console.WriteLine("Default format: " + num); 
    Console.WriteLine("Display a percentage: {0:#%}", num); 
  } 
}

Default format: 0.17
Display a percentage: 17%

Display positive, negative, and zero values differently

using System;  
class MainClass {  
  public static void Main() {  
    double num = 64354.2345; 
    Console.WriteLine("Default format: " + num); 
    Console.WriteLine("Display positive, negative, " + 
                      "and zero values differently."); 
    Console.WriteLine("{0:#.#;(#.##);0.00}", num); 
    num = -num; 
    Console.WriteLine("{0:#.##;(#.##);0.00}", num); 
    num = 0.0; 
    Console.WriteLine("{0:#.##;(#.##);0.00}", num); 
  } 
}

Default format: 64354.2345
Display positive, negative, and zero values differently.
64354.2
(64354.23)
0.00

Display using scientific notation

using System;  
class MainClass {  
  public static void Main() {  
    double num = 64354.2345; 
    Console.WriteLine("Default format: " + num); 
    Console.WriteLine("Use scientific notation: " + 
                      "{0:#.###e+00}", num); 
  } 
}

Default format: 64354.2345
Use scientific notation: 6.435e+04

Display with 2 decimal places

using System;  
class MainClass {  
  public static void Main() {  
    double num = 64354.2345; 
    Console.WriteLine("Default format: " + num); 

    Console.WriteLine("Value with two decimal places: " + 
                      "{0:#.##}", num); 
  } 
}

Default format: 64354.2345
Value with two decimal places: 64354.23

Display with commas and 2 decimal places

using System;  
class MainClass {  
  public static void Main() {  
    double num = 64354.2345; 
    Console.WriteLine("Default format: " + num); 

    Console.WriteLine("Add commas: {0:#,###.##}", num); 
  } 
}

Default format: 64354.2345
Add commas: 64,354.23

Double format specifiers:{0:F2}, {0:N5}, {0:e}, {0:r}, {0:p}, {0:X}, {0:D12}, {0:C}

using System;  
  
class MainClass {  
  public static void Main() {  
    double v = 17688.65849;  
    double v2 = 0.15;  
    int x = 21;  
   
    Console.WriteLine("{0:F2}", v);  
  
    Console.WriteLine("{0:N5}", v);  
  
    Console.WriteLine("{0:e}", v);  
  
    Console.WriteLine("{0:r}", v);  
  
    Console.WriteLine("{0:p}", v2);  
  
    Console.WriteLine("{0:X}", x);  
  
    Console.WriteLine("{0:D12}", x);  
 
    Console.WriteLine("{0:C}", 189.99);  
  }  
}

17688.66
17,688.65849
1.768866e+004
17688.65849
15.00 %
15
000000000021
$189.99

Format double value

using System;  
  
class Example {  
  public static void Main() {  
    double s1 = 1231234.123412341234; 
    Console.WriteLine("{0:#.###}.", s1); 
 
  }  
}

1231234.123.

Scale the value by 1000

using System;  
class MainClass {  
  public static void Main() {  
    double num = 64354.2345; 
    Console.WriteLine("Default format: " + num); 
    Console.WriteLine("Value in 1,000s: " + 
                      "{0:#0,}", num); 
  } 
}

Default format: 64354.2345
Value in 1,000s: 64

Use ToString() to format doubles

using System; 
 
class MainClass { 
  public static void Main() { 
    double v = 17688.65849; 
    double v2 = 0.15; 
    int x = 21; 
  
    string str = v.ToString("F2"); 
    Console.WriteLine(str); 
 
    str = v.ToString("N5"); 
    Console.WriteLine(str); 
 
    str = v.ToString("e"); 
    Console.WriteLine(str); 
 
    str = v.ToString("r"); 
    Console.WriteLine(str); 
 
    str = v2.ToString("p"); 
    Console.WriteLine(str); 
 
    str = x.ToString("X"); 
    Console.WriteLine(str); 
 
    str = x.ToString("D12"); 
    Console.WriteLine(str); 
 
  } 
}

17688.66
17,688.65849
1.768866e+004
17688.65849
15.00 %
15
000000000021