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

ToString(IFormatProvider)

A specific format or precision

Default (current) culture

ToString(String)

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:

[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.

Element

Description

sign

A negative sign or positive sign symbol.

integral-digits

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.

fractional-digits

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

'e'

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

exponential-digits

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.
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

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2015 Microsoft