Double.ToString Method

The return value can be PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol, or a string of the form:

[sign]integral-digits[.[fractional-digits]][e[sign]exponential-digits]

Optional elements are framed in square brackets ([ and ]). Elements that contain the term "digits" consist of a series of numeric characters ranging from 0 to 9. The elements listed in the following table are supported.

Some examples of the return value are "100", "-123,456,789", "123.45e+6", "500", "3.1416", "600", "-0.123", and "-Infinity".

This version of the ToString method implicitly uses the general numeric format specifier ("G") and the NumberFormatInfo for the current culture.

The .NET Framework provides extensive formatting support, which is described in greater detail in the following formatting topics:

• For more information about numeric format specifiers, see Standard Numeric Format Strings and Custom Numeric Format Strings.

• For more information about formatting, see Formatting Types.

The following example uses the default Double.ToString() method to display the string representations of a number of Double values.

double number;

number = 1.6E20;
// Displays 1.6E+20.
Console.WriteLine(number.ToString());

number = 1.6E2;
// Displays 160.
Console.WriteLine(number.ToString());

number = -3.541;
// Displays -3.541.
Console.WriteLine(number.ToString());

number = -1502345222199E-07;
// Displays -150234.5222199.
Console.WriteLine(number.ToString());

number = -15023452221990199574E-09;
// Displays -15023452221.9902.
Console.WriteLine(number.ToString());

number = .60344;
// Displays 0.60344.
Console.WriteLine(number.ToString());

number = .000000001;
// Displays 1E-09.
Console.WriteLine(number.ToString());

The following example illustrates the use of ToString.

      bool done = false;
      string inp;
      do {
         Console.Write("Enter a real number: ");
         inp = Console.ReadLine();
         try {
            d = Double.Parse(inp);
            Console.WriteLine("You entered {0}.", d.ToString());
            done = true;
         } 
         catch (FormatException) {
            Console.WriteLine("You did not enter a number.");
         }
		 catch (ArgumentNullException) {
            Console.WriteLine("You did not supply any input.");
         }
         catch (OverflowException) {
             Console.WriteLine("The value you entered, {0}, is out of range.", inp);      
         }
      } while (!done);

.NET Framework

.NET Framework Client Profile

Portable Class Library

.NET for Windows Store apps

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference

Other Resources