Double.ToString Method (IFormatProvider)

Converts the numeric value of this instance to its equivalent string representation using the specified culture-specific format information.

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

public string ToString(
	IFormatProvider provider
)

Parameters

provider
Type: System.IFormatProvider
An object that supplies culture-specific formatting information.

Return Value

Type: System.String
The string representation of the value of this instance as specified by provider.

Implements

IConvertible.ToString(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".

This instance is formatted with the general numeric format specifier ("G").

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

The provider parameter is an IFormatProvider implementation whose GetFormat method returns a NumberFormatInfo object. Typically, provider is a CultureInfo object or a NumberFormatInfo object. The provider parameter supplies culture-specific information used in formatting. If provider is null, the return value is formatted using the NumberFormatInfo object for the current culture.

To convert a Double value to its string representation using a specified culture and a specific format string, call the Double.ToString(String, IFormatProvider) method.

The following example displays the string representation of two Double values using CultureInfo objects that represent several different cultures.


double value;

value = -16325.62015;
// Display value using the invariant culture.
Console.WriteLine(value.ToString(CultureInfo.InvariantCulture));
// Display value using the en-GB culture.
Console.WriteLine(value.ToString(CultureInfo.CreateSpecificCulture("en-GB")));
// Display value using the de-DE culture.
Console.WriteLine(value.ToString(CultureInfo.CreateSpecificCulture("de-DE")));

value = 16034.125E21;
// Display value using the invariant culture.
Console.WriteLine(value.ToString(CultureInfo.InvariantCulture));
// Display value using the en-GB culture.
Console.WriteLine(value.ToString(CultureInfo.CreateSpecificCulture("en-GB")));
// Display value using the de-DE culture.
Console.WriteLine(value.ToString(CultureInfo.CreateSpecificCulture("de-DE")));
// This example displays the following output to the console:
//       -16325.62015
//       -16325.62015
//       -16325,62015
//       1.6034125E+25
//       1.6034125E+25
//       1,6034125E+25


The following example illustrates the use of ToString, taking a String and an IFormatProvider as parameters.


	public class Temperature : IFormattable {
		// IFormattable.ToString implementation.
		public string ToString(string format, IFormatProvider provider) {
			if( format != null ) {
				if( format.Equals("F") ) {
					return String.Format("{0}'F", this.Value.ToString());
				}
				if( format.Equals("C") ) {
					return String.Format("{0}'C", this.Celsius.ToString());
				}
			}

			return m_value.ToString(format, provider);
		}

		// The value holder
		protected double m_value;

		public double Value {
			get {
				return m_value;
			}
			set {
				m_value = value;
			}
		}

		public double Celsius {
			get {
				return (m_value-32.0)/1.8;
			}
			set {
				m_value = 1.8*value+32.0;
			}
		}
	}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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