C# Format Specifiers—Picture Format Specifiers

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Picture Format Specifiers

Table B-2 lists the valid picture format specifiers supported by the Format method on the predefined numeric types (see the documentation for System.IFormattable in the .NET SDK).

Table B-2. Picture Format Specifiers

This example uses picture-format specifiers on some int values:

using System;
class TestIntegerCustomFormats {
  static void Main( ) {
    int i = 123;
    Console.WriteLine("{0:#0}", i); // 123
    Console.WriteLine("{0:#0;(#0)}", i); // 123
    Console.WriteLine("{0:#0;(#0);<zero>}", i); // 123
    Console.WriteLine("{0:#%}", i); // 12300%
    i = -123;
    Console.WriteLine("{0:#0}", i); // -123
    Console.WriteLine("{0:#0;(#0)}", i); // (123)
    Console.WriteLine("{0:#0;(#0);<zero>}", i); // (123)
    Console.WriteLine("{0:#%}", i); // -12300%
    i = 0;
    Console.WriteLine("{0:#0}", i); // 0
    Console.WriteLine("{0:#0;(#0)}", i); // 0
    Console.WriteLine("{0:#0;(#0);<zero>}", i); // <zero>
    Console.WriteLine("{0:#%}", i); // %
  }
}

The following example uses these picture format specifiers on a variety of double values:

using System;
class TestDoubleCustomFormats {
  static void Main( ) {
    double d = 1.23;
    Console.WriteLine("{0:#.000E+00}", d); // 1.230E+00
    Console.WriteLine(
      "{0:#.000E+00;(#.000E+00)}", d); // 1.230E+00
    Console.WriteLine(
      "{0:#.000E+00;(#.000E+00);<zero>}", d); // 1.230E+00
    Console.WriteLine("{0:#%}", d); // 123%
    d = -1.23;
    Console.WriteLine("{0:#.000E+00}", d); // -1.230E+00
    Console.WriteLine(
      "{0:#.000E+00;(#.000E+00)}", d); // (1.230E+00)
    Console.WriteLine(
      "{0:#.000E+00;(#.000E+00);<zero>}", d); // (1.230E+00)
    Console.WriteLine("{0:#%}", d); // -123%
    d = 0;
    Console.WriteLine("{0:#.000E+00}", d); // 0.000E-01
    Console.WriteLine(
      "{0:#.000E+00;(#.000E+00)}", d); // 0.000E-01
    Console.WriteLine(
      "{0:#.000E+00;(#.000E+00);<zero>}", d); // <zero>
    Console.WriteLine("{0:#%}", d); // %
  }
}