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()
      Dim values() As String = { Nothing, String.Empty, "true", 
                                 "TrueString", "False", "    false    ",
                                 "-1", "0" }
      For Each value In values                                 
         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 
      Next 
   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: 4.5.2, 4.5.1, 4.5, 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

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

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

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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