C# in a Nutshell, Second Edition

Appendix B. Format Specifiers

Table B-1 lists the numeric format specifiers supported by the Format method on the predefined numeric types.

Table B-1. Numeric Format Specifiers

Specifier	String result	Datatype
C[ n ]	$XX,XX.XX ($XX,XXX.XX)	Currency
D[ n ]	[-]XXXXXXX	Decimal
E[ n ] or e[ n ]	[-]X.XXXXXXE+xxx [-]X.XXXXXXe+xxx [-]X.XXXXXXE-xxx [-]X.XXXXXXe-xxx	Exponent
F[ n ]	[-]XXXXXXX.XX	Fixed point
G[ n ]	General or scientific	General
N[ n ]	[-]XX,XXX.XX	Number
X[ n ] or x[ n ]	Hex representation	Hex

This example uses numeric format specifiers without precision specifiers:

using System;
class TestDefaultFormats {
  static void Main( ) {
    int i = 654321;
    Console.WriteLine("{0:C}", i); // $654,321.00
    Console.WriteLine("{0:D}", i); // 654321
    Console.WriteLine("{0:E}", i); // 6.543210E+005
    Console.WriteLine("{0:F}", i); // 654321.00
    Console.WriteLine("{0:G}", i); // 654321
    Console.WriteLine("{0:N}", i); // 654,321.00
    Console.WriteLine("{0:X}", i); // 9FBF1
    Console.WriteLine("{0:x}", i); // 9fbf1
  }
}

This example uses numeric format specifiers with precision specifiers on a variety of int values:

using System; class TestIntegerFormats { static void Main( ) { int i = 123; Console.WriteLine("{0:C6}", i); // $123.000000 Console.WriteLine("{0:D6}", i); // 000123 Console.WriteLine("{0:E6}", i); // 1.230000E+002 Console.WriteLine("{0:G6}", i); // 123 Console.WriteLine("{0:N6}", i); // 123.000000 Console.WriteLine("{0:X6}", i); // 00007B i ...