Double.ToString Method ()


Converts the numeric value of this instance to its equivalent string representation.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public override string ToString()

Return Value

Type: System.String

The string representation of the value of this instance.

The ToString() method formats a Double value in the default ("G", or general) format of the current culture. If you want to specify a different format, precision, or culture, use the other overloads of the ToString method, as follows:

To use format

For culture

Use the overload

Default ("G") format

A specific culture


A specific format or precision

Default (current) culture


A specific format or precision

A specific culture

ToString(String, IFormatProvider)

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


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.




A negative sign or positive sign symbol.


A series of digits specifying the integral part of the number. Integral-digits can be absent if there are fractional-digits.


A culture-specific decimal point symbol.


A series of digits specifying the fractional part of the number.


A lowercase character 'e', indicating exponential (scientific) notation.


A series of digits specifying an exponent.

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

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

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.

number = 1.6E2;
// Displays 160.

number = -3.541;
// Displays -3.541.

number = -1502345222199E-07;
// Displays -150234.5222199.

number = -15023452221990199574E-09;
// Displays -15023452221.9902.

number = .60344;
// Displays 0.60344.

number = .000000001;
// Displays 1E-09.

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);

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top