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Int64.ToString Method (String, IFormatProvider)

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

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

public string ToString(
	string format,
	IFormatProvider provider


Type: System.String
A numeric format string.
Type: System.IFormatProvider
An object that supplies culture-specific formatting information about this instance.

Return Value

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


IFormattable.ToString(String, IFormatProvider)


format is invalid or not supported.

The format parameter can be either a standard or a custom numeric format string. All standard numeric format strings other than "R" (or "r") are supported, as are all custom numeric format characters. If format is null or an empty string (""), the return value for this instance is formatted with the general numeric format specifier ("G").

The provider parameter is an object that implements the IFormatProvider interface. Its GetFormat method returns a NumberFormatInfo object that provides culture-specific information about the format of the string that is returned by this method. The object that implements IFormatProvider can be any of the following:

If provider is null or a NumberFormatInfo object cannot be obtained from provider, the return value for this instance is formatted with the NumberFormatInfo for the current culture.

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

The following example displays a positive and a negative value using each of the supported standard numeric format specifiers for three different cultures.

// Define cultures whose formatting conventions are to be used.
CultureInfo[] cultures = {CultureInfo.CreateSpecificCulture("en-US"), 
                          CultureInfo.CreateSpecificCulture("es-ES") };
long positiveNumber = 1679;
long negativeNumber = -3045;
string[] specifiers = {"G", "C", "D8", "E2", "F", "N", "P", "X8"}; 

foreach (string specifier in specifiers)
   foreach (CultureInfo culture in cultures)
      // Display values with "G" format specifier.
      Console.WriteLine("{0} format using {1} culture: {2, 16} {3, 16}",  
                        specifier, culture.Name, 
                        positiveNumber.ToString(specifier, culture), 
                        negativeNumber.ToString(specifier, culture));
// The example displays the following output to the console:
//    G format using en-US culture:             1679            -3045
//    G format using fr-FR culture:             1679            -3045
//    G format using es-ES culture:             1679            -3045
//    C format using en-US culture:        $1,679.00      ($3,045.00)
//    C format using fr-FR culture:       1�679,00 ?      -3�045,00 ?
//    C format using es-ES culture:       1.679,00 ?      -3.045,00 ?
//    D8 format using en-US culture:         00001679        -00003045
//    D8 format using fr-FR culture:         00001679        -00003045
//    D8 format using es-ES culture:         00001679        -00003045
//    E2 format using en-US culture:        1.68E+003       -3.05E+003
//    E2 format using fr-FR culture:        1,68E+003       -3,05E+003
//    E2 format using es-ES culture:        1,68E+003       -3,05E+003
//    F format using en-US culture:          1679.00         -3045.00
//    F format using fr-FR culture:          1679,00         -3045,00
//    F format using es-ES culture:          1679,00         -3045,00
//    N format using en-US culture:         1,679.00        -3,045.00
//    N format using fr-FR culture:         1�679,00        -3�045,00
//    N format using es-ES culture:         1.679,00        -3.045,00
//    P format using en-US culture:     167,900.00 %    -304,500.00 %
//    P format using fr-FR culture:     167�900,00 %    -304�500,00 %
//    P format using es-ES culture:     167.900,00 %    -304.500,00 %
//    X8 format using en-US culture:         0000068F         FFFFF41B
//    X8 format using fr-FR culture:         0000068F         FFFFF41B
//    X8 format using es-ES culture:         0000068F         FFFFF41B

.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.