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Byte.TryParse Method (String, Byte)

Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

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

'Declaration
Public Shared Function TryParse ( _
	s As String, _
	<OutAttribute> ByRef result As Byte _
) As Boolean

Parameters

s
Type: System.String

A string that contains a number to convert. The string is interpreted using the Integer style.

result
Type: System.Byte

When this method returns, contains the Byte value equivalent to the number contained in s if the conversion succeeded, or zero if the conversion failed. This parameter is passed uninitialized.

Return Value

Type: System.Boolean
true if s was converted successfully; otherwise, false.

The conversion fails and the method returns false if the s parameter is not in the correct format, if it is Nothing or String.Empty, or if it represents a number less than MinValue or greater than MaxValue.

The Byte.TryParse(String, Byte) method is similar to the Byte.Parse(String) method, except that TryParse(String, Byte) does not throw an exception if the conversion fails.

The s parameter should be the string representation of a number in the following form:

[ws][sign]digits[ws]

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

Element

Description

ws

Optional white space.

sign

An optional positive sign, as specified by the NumberFormatInfo.PositiveSign property of the current culture.

digits

A sequence of decimal digits that range from 0 to 9.

The s parameter is interpreted using the Integer style. In addition to the byte value's decimal digits, only leading and trailing spaces together with a leading sign are allowed. (If the sign is present, it must be a positive sign or the method throws an OverflowException.) To explicitly define the style elements together with the culture-specific formatting information that can be present in s, use the Byte.Parse(String, NumberStyles, IFormatProvider) method.

The s parameter is parsed using the formatting information in a NumberFormatInfo object for the current culture. For more information, see NumberFormatInfo.CurrentInfo.

This overload of the Byte.TryParse(String, Byte) method interprets all digits in the s parameter as decimal digits. To parse the string representation of a hexadecimal number, call the Byte.TryParse(String, NumberStyles, IFormatProvider, Byte) overload.

The following example calls the TryParse(String, Byte) method with a number of different string values.

Module ByteConversion
   Public Sub Main()
      Dim byteString As String = Nothing
      CallTryParse(byteString)

      byteString = String.Empty
      CallTryParse(byteString)

      byteString = "1024"
      CallTryParse(byteString)

      byteString = "100.1"
      CallTryParse(byteString)

      byteString = "100"
      CallTryParse(byteString)

      byteString = "+100"
      CallTryParse(byteString)

      byteString = "-100"
      CallTryParse(byteString)

      byteString = "000000000000000100"
      CallTryParse(byteString)

      byteString = "00,100"      
      CallTryParse(byteString)

      byteString = "   20   "
      CallTryParse(byteString)

      byteString = "FF"
      CallTryParse(byteString)

      byteString = "0x1F"
      CallTryParse(byteString)
   End Sub 

   Private Sub CallTryParse(stringToConvert As String)  
      Dim byteValue As Byte 
      Dim result As Boolean = Byte.TryParse(stringToConvert, byteValue)
      If result Then
         Console.WriteLine("Converted '{0}' to {1}", _
                        stringToConvert, byteValue)
      Else 
         If stringToConvert Is Nothing Then stringToConvert = ""
         Console.WriteLine("Attempted conversion of '{0}' failed.", _
                           stringToConvert.ToString())
      End If                         
   End Sub 
End Module 
' The example displays the following output to the console: 
'       Attempted conversion of '' failed. 
'       Attempted conversion of '' failed. 
'       Attempted conversion of '1024' failed. 
'       Attempted conversion of '100.1' failed. 
'       Converted '100' to 100 
'       Converted '+100' to 100 
'       Attempted conversion of '-100' failed. 
'       Converted '000000000000000100' to 100 
'       Attempted conversion of '00,100' failed. 
'       Converted '   20   ' to 20 
'       Attempted conversion of 'FF' failed. 
'       Attempted conversion of '0x1F' failed.

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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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