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ToString Method (String)

Single.ToString Method (String)

Converts the numeric value of this instance to its equivalent string representation, using the specified format.

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

public string ToString(
	string format


Type: System.String
A numeric format string.

Return Value

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


format is invalid.

The return value can be PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol, or the string representation of the value of the current instance, as specified by format.

The format parameter can be any valid standard numeric format specifier except for D and X, as well as any combination of custom numeric format specifiers. If format is null or an empty string, the return value 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 return value is formatted using the NumberFormatInfo object for the current culture. To apply the formatting conventions of a specified culture, call the Single.ToString(String, IFormatProvider) method.

By default, the return value only contains 7 digits of precision although a maximum of 9 digits is maintained internally. If the value of this instance has greater than 7 digits, ToString(String) returns PositiveInfinitySymbol or NegativeInfinitySymbol instead of the expected number. If you require more precision, specify format with the "G9" format specification, which always returns 9 digits of precision, or "R", which returns 7 digits if the number can be represented with that precision or 9 digits if the number can only be represented with maximum precision.

The following example displays several Single values using each of the supported standard numeric format specifiers together with two custom numeric format strings. One of those custom format strings illustrates how to pad a Single value with leading zeros. In converting the numeric values to strings, the example uses the formatting conventions of the en-US culture.

float[] numbers= { 1054.32179F, -195489100.8377F, 1.0437E21F, 
                   -1.0573e-05F };
string[] specifiers = { "C", "E", "e", "F", "G", "N", "P", 
                        "R", "#,000.000", "0.###E-000",
                        "000,000,000,000.00###" };

foreach (float number in numbers)
   Console.WriteLine("Formatting of {0}:", number);
   foreach (string specifier in specifiers)
      Console.WriteLine("   {0,5}: {1}", 
                        specifier, number.ToString(specifier));

// The example displays the following output to the console:
//       Formatting of 1054.32179:
//              C: $1,054.32
//              E: 1.054322E+003
//              e: 1.054322e+003
//              F: 1054.32
//              G: 1054.32179
//              N: 1,054.32
//              P: 105,432.18 %
//              R: 1054.32179
//          #,000.000: 1,054.322
//          0.###E-000: 1.054E003
//          000,000,000,000.00###: 000,000,001,054.322
//       Formatting of -195489100.8377:
//              C: ($195,489,100.84)
//              E: -1.954891E+008
//              e: -1.954891e+008
//              F: -195489100.84
//              G: -195489100.8377
//              N: -195,489,100.84
//              P: -19,548,910,083.77 %
//              R: -195489100.8377
//          #,000.000: -195,489,100.838
//          0.###E-000: -1.955E008
//          000,000,000,000.00###: -000,195,489,100.00
//       Formatting of 1.0437E+21:
//              C: $1,043,700,000,000,000,000,000.00
//              E: 1.043700E+021
//              e: 1.043700e+021
//              F: 1043700000000000000000.00
//              G: 1.0437E+21
//              N: 1,043,700,000,000,000,000,000.00
//              P: 104,370,000,000,000,000,000,000.00 %
//              R: 1.0437E+21
//          #,000.000: 1,043,700,000,000,000,000,000.000
//          0.###E-000: 1.044E021
//          000,000,000,000.00###: 1,043,700,000,000,000,000,000.00
//       Formatting of -1.0573E-05:
//              C: $0.00
//              E: -1.057300E-005
//              e: -1.057300e-005
//              F: 0.00
//              G: -1.0573E-05
//              N: 0.00
//              P: 0.00 %
//              R: -1.0573E-05
//          #,000.000: 000.000
//          0.###E-000: -1.057E-005
//          000,000,000,000.00###: -000,000,000,000.00001 

.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

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.

Community Additions

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