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Convert.ToBoolean Method (String)

Converts the specified string representation of a logical value to its Boolean equivalent.

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

'Declaration
Public Shared Function ToBoolean ( _
	value As String _
) As Boolean

Parameters

value
Type: System.String
A string that contains the value of either Boolean.TrueString or Boolean.FalseString.

Return Value

Type: System.Boolean
true if value equals TrueString, or false if value equals FalseString or Nothing.

ExceptionCondition
FormatException

value is not equal to TrueString or FalseString.

For a successful conversion to occur, the value parameter must equal either Boolean.TrueString, a constant whose value is True, Boolean.FalseString, a constant whose value is False, or it must be Nothing. In comparing value with Boolean.TrueString and Boolean.FalseString, the method ignores case as well as leading and trailing white space.

If you prefer not to handle an exception if the conversion fails, you can call the Boolean.TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.

The following example uses the Convert.ToBoolean(String) method to convert various strings to Boolean values.


Module BooleanConversion
   Public Sub Main()
      ConvertToBoolean(Nothing)
      ConvertToBoolean(String.Empty)
      ConvertToBoolean("true")
      ConvertToBoolean("TrueString")
      ConvertToBoolean("False")
      ConvertToBoolean("    false    ")
      ConvertToBoolean("-1")
      ConvertToBoolean("0")
   End Sub

   Private Sub ConvertToBoolean(value As String)
      Try
         Console.WriteLine("Converted '{0}' to {1}.", value, _ 
                           Convert.ToBoolean(value))
      Catch e As FormatException
         Console.WriteLine("Unable to convert '{0}' to a Boolean.", value)
      End Try
   End Sub
End Module
' The example displays the following output to the console:
'       Converted '' to False.
'       Unable to convert '' to a Boolean.
'       Converted 'true' to True.
'       Unable to convert 'TrueString' to a Boolean.
'       Converted 'False' to False.
'       Converted '    false    ' to False.
'       Unable to convert '-1' to a Boolean.
'       Unable to convert '0' to a Boolean.


.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.

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