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Single.Parse Method (String)

Updated: August 2009

Converts the string representation of a number to its single-precision floating-point number equivalent.

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

public static float Parse(
	string s


Type: System.String

A string that contains a number to convert.

Return Value

Type: System.Single
A single-precision floating-point number equivalent to the numeric value or symbol specified in s.


s is null.


s is not a number in a valid format.


s represents a number less than MinValue or greater than MaxValue.

The s parameter can contain the current culture's PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol, or a string of the form:

[ws][sign] [integral-digits[,]]integral-digits[.[fractional-digits]][e[sign]exponential-digits][ws]

Elements in square brackets ([ and ]) are optional. The following table describes each element.




A series of white space characters.


A negative sign symbol or a positive sign symbol. Valid sign characters are determined by the NumberFormatInfo.NegativeSign and NumberFormatInfo.PositiveSign properties of the current culture. Only a leading sign can be used.


A series of digits ranging from 0 to 9 that specify the integral part of the number. Runs of integral-digits can be partitioned by a group-separator symbol. For example, in some cultures a comma (,) separates groups of thousands. The integral-digits element can be absent if the string contains the fractional-digits element.


A culture-specific thousands separator symbol.


A culture-specific decimal point symbol.


A series of digits ranging from 0 to 9 that specify the fractional part of the number.


The "e" or "E" character, which indicates that the value is represented in exponential (scientific) notation.


A series of digits ranging from 0 to 9 that specify an exponent.

The s parameter is interpreted using a combination of the NumberStyles.Float and NumberStyles.AllowThousands flags. This means that white space and thousands separators are allowed but currency symbols are not. To explicitly define the elements (such as currency symbols, thousands separators, and white space) that can be present in s, use the Parse(String, NumberStyles) method overload.

The s parameter is parsed by using the formatting information in a NumberFormatInfo object that is initialized for the current system culture. For more information, see CurrentInfo. To parse a string by using the formatting information of a specific culture, use the Parse(String, IFormatProvider) or Parse(String, NumberStyles, IFormatProvider) method.

Ordinarily, if you pass the Parse method a string that is created by calling the ToString method, the original Single value is returned. However, because of a loss of precision, the values may not be equal.

If a separator is encountered in the s parameter during a parse operation, and the applicable currency or number decimal and group separators are the same, the parse operation assumes that the separator is a decimal separator rather than a group separator. For more information about separators, see CurrencyDecimalSeparator, NumberDecimalSeparator, CurrencyGroupSeparator, and NumberGroupSeparator.

The following example uses the Parse(String) method to convert an array of strings to equivalent Single values.

using System;

public class Example
   public static void Main()
      string[] values = { "100", "(100)", "-123,456,789", "123.45e+6", 
                          "+500", "5e2", "3.1416", "600.", "-.123", 
                          "-Infinity", "-1E-16", Double.MaxValue.ToString(), 
                          Single.MinValue.ToString(), String.Empty };
      foreach (string value in values)
         try {   
            float number = Single.Parse(value);
            Console.WriteLine("{0} -> {1}", value, number);
         catch (FormatException) {
            Console.WriteLine("'{0}' is not in a valid format.", value);
         catch (OverflowException) {
            Console.WriteLine("{0} is outside the range of a Single.", value);
// The example displays the following output: 
//       100 -> 100 
//       '(100)' is not in a valid format. 
//       -123,456,789 -> -1.234568E+08 
//       123.45e+6 -> 1.2345E+08 
//       +500 -> 500 
//       5e2 -> 500 
//       3.1416 -> 3.1416 
//       600. -> 600 
//       -.123 -> -0.123 
//       -Infinity -> -Infinity 
//       -1E-16 -> -1E-16 
//       1.79769313486232E+308 is outside the range of a Single. 
//       -3.402823E+38 -> -3.402823E+38 
//       '' is not in a valid format.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

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

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0




August 2009

Revised extensively.

Information enhancement.

© 2018 Microsoft