Standard Numeric Format Strings 

Standard numeric format strings are used to format common numeric types. A standard numeric format string takes the form Axx, where A is an alphabetic character called the format specifier, and xx is an optional integer called the precision specifier. The precision specifier ranges from 0 to 99 and affects the number of digits in the result. Any numeric format string that contains more than one alphabetic character, including white space, is interpreted as a custom numeric format string.

The following table describes the standard numeric format specifiers. For examples of the output produced by each format specifier, see Standard Numeric Format Strings Output Examples. For more information, see the notes that follow the table.

Notes

Control Panel Settings

The settings in the Regional and Language Options item in Control Panel influence the result string produced by a formatting operation. Those settings are used to initialize the NumberFormatInfo object associated with the current thread culture, and the current thread culture provides values used to govern formatting. Computers using different settings will generate different result strings.

NumberFormatInfo Properties

Formatting is influenced by properties of the current NumberFormatInfo object, which is provided implicitly by the current thread culture or explicitly by the IFormatProvider parameter of the method that invokes formatting. Specify a NumberFormatInfo or CultureInfo object for that parameter.

Integral and Floating-Point Numeric Types

Some descriptions of standard numeric format specifiers refer to integral or floating-point numeric types. The integral numeric types are Byte, SByte, Int16, Int32, Int64, UInt16, UInt32, and UInt64. The floating-point numeric types are Decimal, Single, and Double.

Floating-Point Infinities and NaN

Note that regardless of the format string, if the value of a Single or Double floating-point type is positive infinity, negative infinity, or Not a Number (NaN), the formatted string is the value of the respective PositiveInfinitySymbol, NegativeInfinitySymbol, or NaNSymbol property specified by the currently applicable NumberFormatInfo object.

Example

The following code example formats an integral and a floating-point numeric value using the thread current culture, a specified culture, and all the standard numeric format specifiers. This code example uses two particular numeric types, but would yield similar results for any of the numeric base types (Byte, SByte, Int16, Int32, Int64, UInt16, UInt32, UInt64, Decimal, Single, and Double).

' This code example demonstrates the ToString(String) and 
' ToString(String, IFormatProvider) methods for integral and
' floating-point numbers, in conjunction with the standard 
' numeric format specifiers.
' This code example uses the System.Int32 integral type and 
' the System.Double floating-point type, but would yield 
' similar results for any of the numeric types. The integral 
' numeric types are System.Byte, SByte, Int16, Int32, Int64, 
' UInt16, UInt32, and UInt64. The floating-point numeric types 
' are Decimal, Single, and Double.

Imports System
Imports System.Globalization
Imports System.Threading

Class Sample
    Public Shared Sub Main() 
        ' Format a negative integer or floating-point number in various ways.
        Dim integralVal As Integer = -12345
        Dim floatingVal As Double  = -1234.567
        
        Dim msgCurrency As String =    "(C) Currency: . . . . . . "
        Dim msgDecimal As String =     "(D) Decimal:. . . . . . . "
        Dim msgScientific As String =  "(E) Scientific: . . . . . "
        Dim msgFixedPoint As String =  "(F) Fixed point:. . . . . "
        Dim msgGeneral As String =     "(G) General (default):. . "
        Dim msgNumber As String =      "(N) Number: . . . . . . . "
        Dim msgPercent As String =     "(P) Percent:. . . . . . . "
        Dim msgRoundTrip As String =   "(R) Round-trip: . . . . . "
        Dim msgHexadecimal As String = "(X) Hexadecimal:. . . . . "
        
        Dim msg1 As String = "Use ToString(String) and the current thread culture." + vbLf
        Dim msg2 As String = "Use ToString(String, IFormatProvider) and a specified culture." + vbLf
        Dim msgCulture As String = "Culture:"
        Dim msgIntegralVal As String = "Integral value:"
        Dim msgFloatingVal As String = "Floating-point value:"
        
        Dim ci As CultureInfo
        '
        Console.Clear()
        Console.WriteLine("Standard Numeric Format Specifiers:" & vbLf)
        ' Display the values.
        Console.WriteLine(msg1)
        
        ' Display the thread current culture, which is used to format the values.
        ci = Thread.CurrentThread.CurrentCulture
        Console.WriteLine("{0,-26}{1}", msgCulture, ci.DisplayName)
        
        ' Display the integral and floating-point values.
        Console.WriteLine("{0,-26}{1}", msgIntegralVal, integralVal)
        Console.WriteLine("{0,-26}{1}", msgFloatingVal, floatingVal)
        Console.WriteLine()
        
        ' Use the format specifiers that are only for integral types.
        Console.WriteLine("Format specifiers only for integral types:")
        Console.WriteLine(msgDecimal     & integralVal.ToString("D"))
        Console.WriteLine(msgHexadecimal & integralVal.ToString("X"))
        Console.WriteLine()
        
        ' Use the format specifier that is only for the Single and Double 
        ' floating-point types.
        Console.WriteLine("Format specifier only for the Single and Double types:")
        Console.WriteLine(msgRoundTrip   & floatingVal.ToString("R"))
        Console.WriteLine()
        
        ' Use the format specifiers that are for integral or floating-point types.
        Console.WriteLine("Format specifiers for integral or floating-point types:")
        Console.WriteLine(msgCurrency    & floatingVal.ToString("C"))
        Console.WriteLine(msgScientific  & floatingVal.ToString("E"))
        Console.WriteLine(msgFixedPoint  & floatingVal.ToString("F"))
        Console.WriteLine(msgGeneral     & floatingVal.ToString("G"))
        Console.WriteLine(msgNumber      & floatingVal.ToString("N"))
        Console.WriteLine(msgPercent     & floatingVal.ToString("P"))
        Console.WriteLine()
        
        ' Display the same values using a CultureInfo object. The CultureInfo class 
        ' implements IFormatProvider.
        Console.WriteLine(msg2)
        
        ' Display the culture used to format the values. 
        ' Create a European culture and change its currency symbol to "euro" because 
        ' this particular code example uses a thread current UI culture that cannot 
        ' display the euro symbol (€).
        ci = New CultureInfo("de-DE")
        ci.NumberFormat.CurrencySymbol = "euro"
        Console.WriteLine("{0,-26}{1}", msgCulture, ci.DisplayName)
        
        ' Display the integral and floating-point values.
        Console.WriteLine("{0,-26}{1}", msgIntegralVal, integralVal)
        Console.WriteLine("{0,-26}{1}", msgFloatingVal, floatingVal)
        Console.WriteLine()
        
        ' Use the format specifiers that are only for integral types.
        Console.WriteLine("Format specifiers only for integral types:")
        Console.WriteLine(msgDecimal     & integralVal.ToString("D", ci))
        Console.WriteLine(msgHexadecimal & integralVal.ToString("X", ci))
        Console.WriteLine()
        
        ' Use the format specifier that is only for the Single and Double 
        ' floating-point types.
        Console.WriteLine("Format specifier only for the Single and Double types:")
        Console.WriteLine(msgRoundTrip   & floatingVal.ToString("R", ci))
        Console.WriteLine()
        
        ' Use the format specifiers that are for integral or floating-point types.
        Console.WriteLine("Format specifiers for integral or floating-point types:")
        Console.WriteLine(msgCurrency    & floatingVal.ToString("C", ci))
        Console.WriteLine(msgScientific  & floatingVal.ToString("E", ci))
        Console.WriteLine(msgFixedPoint  & floatingVal.ToString("F", ci))
        Console.WriteLine(msgGeneral     & floatingVal.ToString("G", ci))
        Console.WriteLine(msgNumber      & floatingVal.ToString("N", ci))
        Console.WriteLine(msgPercent     & floatingVal.ToString("P", ci))
        Console.WriteLine()
    End Sub 'Main
End Class 'Sample
'
'This code example produces the following results:
'
'Standard Numeric Format Specifiers:
'
'Use ToString(String) and the current thread culture.
'
'Culture:                  English (United States)
'Integral value:           -12345
'Floating-point value:     -1234.567
'
'Format specifiers only for integral types:
'(D) Decimal:. . . . . . . -12345
'(X) Hexadecimal:. . . . . FFFFCFC7
'
'Format specifier only for the Single and Double types:
'(R) Round-trip: . . . . . -1234.567
'
'Format specifiers for integral or floating-point types:
'(C) Currency: . . . . . . ($1,234.57)
'(E) Scientific: . . . . . -1.234567E+003
'(F) Fixed point:. . . . . -1234.57
'(G) General (default):. . -1234.567
'(N) Number: . . . . . . . -1,234.57
'(P) Percent:. . . . . . . -123,456.70 %
'
'Use ToString(String, IFormatProvider) and a specified culture.
'
'Culture:                  German (Germany)
'Integral value:           -12345
'Floating-point value:     -1234.567
'
'Format specifiers only for integral types:
'(D) Decimal:. . . . . . . -12345
'(X) Hexadecimal:. . . . . FFFFCFC7
'
'Format specifier only for the Single and Double types:
'(R) Round-trip: . . . . . -1234,567
'
'Format specifiers for integral or floating-point types:
'(C) Currency: . . . . . . -1.234,57 euro
'(E) Scientific: . . . . . -1,234567E+003
'(F) Fixed point:. . . . . -1234,57
'(G) General (default):. . -1234,567
'(N) Number: . . . . . . . -1.234,57
'(P) Percent:. . . . . . . -123.456,70%
'

// This code example demonstrates the ToString(String) and 
// ToString(String, IFormatProvider) methods for integral and
// floating-point numbers, in conjunction with the standard 
// numeric format specifiers.
// This code example uses the System.Int32 integral type and 
// the System.Double floating-point type, but would yield 
// similar results for any of the numeric types. The integral 
// numeric types are System.Byte, SByte, Int16, Int32, Int64, 
// UInt16, UInt32, and UInt64. The floating-point numeric types 
// are Decimal, Single, and Double.

using System;
using System.Globalization;
using System.Threading;

class Sample 
{
    public static void Main() 
    {
// Format a negative integer or floating-point number in various ways.
    int    integralVal = -12345;
    double floatingVal = -1234.567d;

    string msgCurrency =    "(C) Currency: . . . . . . ";
    string msgDecimal  =    "(D) Decimal:. . . . . . . ";
    string msgScientific =  "(E) Scientific: . . . . . ";
    string msgFixedPoint =  "(F) Fixed point:. . . . . ";
    string msgGeneral =     "(G) General (default):. . ";
    string msgNumber =      "(N) Number: . . . . . . . ";
    string msgPercent =     "(P) Percent:. . . . . . . ";
    string msgRoundTrip =   "(R) Round-trip: . . . . . ";
    string msgHexadecimal = "(X) Hexadecimal:. . . . . ";

    string msg1 = "Use ToString(String) and the current thread culture.\n";
    string msg2 = "Use ToString(String, IFormatProvider) and a specified culture.\n";
    string msgCulture     = "Culture:";
    string msgIntegralVal = "Integral value:";
    string msgFloatingVal = "Floating-point value:";

    CultureInfo ci;
//
    Console.Clear();
    Console.WriteLine("Standard Numeric Format Specifiers:\n");
// Display the values.
    Console.WriteLine(msg1);

// Display the thread current culture, which is used to format the values.
    ci = Thread.CurrentThread.CurrentCulture;
    Console.WriteLine("{0,-26}{1}", msgCulture, ci.DisplayName);

// Display the integral and floating-point values.
    Console.WriteLine("{0,-26}{1}", msgIntegralVal, integralVal);
    Console.WriteLine("{0,-26}{1}", msgFloatingVal, floatingVal);
    Console.WriteLine();

// Use the format specifiers that are only for integral types.
    Console.WriteLine("Format specifiers only for integral types:");
    Console.WriteLine(msgDecimal     + integralVal.ToString("D"));
    Console.WriteLine(msgHexadecimal + integralVal.ToString("X"));
    Console.WriteLine();

// Use the format specifier that is only for the Single and Double 
// floating-point types.
    Console.WriteLine("Format specifier only for the Single and Double types:");
    Console.WriteLine(msgRoundTrip   + floatingVal.ToString("R"));
    Console.WriteLine();

// Use the format specifiers that are for integral or floating-point types.
    Console.WriteLine("Format specifiers for integral or floating-point types:");
    Console.WriteLine(msgCurrency    + floatingVal.ToString("C"));
    Console.WriteLine(msgScientific  + floatingVal.ToString("E"));
    Console.WriteLine(msgFixedPoint  + floatingVal.ToString("F"));
    Console.WriteLine(msgGeneral     + floatingVal.ToString("G"));
    Console.WriteLine(msgNumber      + floatingVal.ToString("N"));
    Console.WriteLine(msgPercent     + floatingVal.ToString("P"));
    Console.WriteLine();

// Display the same values using a CultureInfo object. The CultureInfo class 
// implements IFormatProvider.
    Console.WriteLine(msg2);

// Display the culture used to format the values. 
// Create a European culture and change its currency symbol to "euro" because 
// this particular code example uses a thread current UI culture that cannot 
// display the euro symbol (€).
    ci = new CultureInfo("de-DE");
    ci.NumberFormat.CurrencySymbol = "euro";
    Console.WriteLine("{0,-26}{1}", msgCulture, ci.DisplayName);

// Display the integral and floating-point values.
    Console.WriteLine("{0,-26}{1}", msgIntegralVal, integralVal);
    Console.WriteLine("{0,-26}{1}", msgFloatingVal, floatingVal);
    Console.WriteLine();

// Use the format specifiers that are only for integral types.
    Console.WriteLine("Format specifiers only for integral types:");
    Console.WriteLine(msgDecimal     + integralVal.ToString("D", ci));
    Console.WriteLine(msgHexadecimal + integralVal.ToString("X", ci));
    Console.WriteLine();

// Use the format specifier that is only for the Single and Double 
// floating-point types.
    Console.WriteLine("Format specifier only for the Single and Double types:");
    Console.WriteLine(msgRoundTrip   + floatingVal.ToString("R", ci));
    Console.WriteLine();

// Use the format specifiers that are for integral or floating-point types.
    Console.WriteLine("Format specifiers for integral or floating-point types:");
    Console.WriteLine(msgCurrency    + floatingVal.ToString("C", ci));
    Console.WriteLine(msgScientific  + floatingVal.ToString("E", ci));
    Console.WriteLine(msgFixedPoint  + floatingVal.ToString("F", ci));
    Console.WriteLine(msgGeneral     + floatingVal.ToString("G", ci));
    Console.WriteLine(msgNumber      + floatingVal.ToString("N", ci));
    Console.WriteLine(msgPercent     + floatingVal.ToString("P", ci));
    Console.WriteLine();
    }
}
/*
This code example produces the following results:

Standard Numeric Format Specifiers:

Use ToString(String) and the current thread culture.

Culture:                  English (United States)
Integral value:           -12345
Floating-point value:     -1234.567

Format specifiers only for integral types:
(D) Decimal:. . . . . . . -12345
(X) Hexadecimal:. . . . . FFFFCFC7

Format specifier only for the Single and Double types:
(R) Round-trip: . . . . . -1234.567

Format specifiers for integral or floating-point types:
(C) Currency: . . . . . . ($1,234.57)
(E) Scientific: . . . . . -1.234567E+003
(F) Fixed point:. . . . . -1234.57
(G) General (default):. . -1234.567
(N) Number: . . . . . . . -1,234.57
(P) Percent:. . . . . . . -123,456.70 %

Use ToString(String, IFormatProvider) and a specified culture.

Culture:                  German (Germany)
Integral value:           -12345
Floating-point value:     -1234.567

Format specifiers only for integral types:
(D) Decimal:. . . . . . . -12345
(X) Hexadecimal:. . . . . FFFFCFC7

Format specifier only for the Single and Double types:
(R) Round-trip: . . . . . -1234,567

Format specifiers for integral or floating-point types:
(C) Currency: . . . . . . -1.234,57 euro
(E) Scientific: . . . . . -1,234567E+003
(F) Fixed point:. . . . . -1234,57
(G) General (default):. . -1234,567
(N) Number: . . . . . . . -1.234,57
(P) Percent:. . . . . . . -123.456,70%

*/

See Also

Reference

NumberFormatInfo

Concepts

Numeric Format Strings
Standard Numeric Format Strings Output Examples
Custom Numeric Format Strings

Other Resources

Formatting Types