Updated: September 2010
Converts the specified string representation of a logical value to its Boolean equivalent, or throws an exception if the string is not equivalent to the value of Boolean
Assembly: mscorlib (in mscorlib.dll)
Public Shared Function Parse ( _
value As String _
) As Booleanpublic static bool Parse(
string value
)public:
static bool Parse(
String^ value
)static member Parse :
value:string -> bool
Parameters
- value
- Type: System
. . :: . String
A string containing the value to convert.
Return Value
Type: Systemtrue if value is equivalent to the value of the Boolean
| Exception | Condition |
|---|---|
| ArgumentNullException | value is |
| FormatException | value is not equivalent to the value of the TrueString or FalseString field. |
The value parameter, optionally preceded or trailed by white space, must contain a string that is equivalent to the value of either the Boolean
The following example calls the Parse method to parse an array of strings. Note that the parse operation succeeds only if the string to be parsed is "True" (the value of the TrueString field) or "False" (the value of the FalseString field) in a case-insensitive comparison.
Module Example
Public Sub Main()
Dim values() As String = { Nothing, String.Empty, "True", "False",
"true", "false", " true ", "0",
"1", "-1", "string" }
For Each value In values
Try
Dim flag As Boolean = Boolean.Parse(value)
Console.WriteLine("'{0}' --> {1}", value, flag)
Catch e As ArgumentException
Console.WriteLine("Cannot parse a null string.")
Catch e As FormatException
Console.WriteLine("Cannot parse '{0}'.", value)
End Try
Next
End Sub
End Module
' The example displays the following output:
' Cannot parse a null string.
' Cannot parse ''.
' 'True' --> True
' 'False' --> False
' 'true' --> True
' 'false' --> False
' ' true ' --> True
' Cannot parse '0'.
' Cannot parse '1'.
' Cannot parse '-1'.
' Cannot parse 'string'.
using System;
public class Example
{
public static void Main()
{
string[] values = { null, String.Empty, "True", "False",
"true", "false", " true ", "0",
"1", "-1", "string" };
foreach (var value in values) {
try {
bool flag = Boolean.Parse(value);
Console.WriteLine("'{0}' --> {1}", value, flag);
}
catch (ArgumentException) {
Console.WriteLine("Cannot parse a null string.");
}
catch (FormatException) {
Console.WriteLine("Cannot parse '{0}'.", value);
}
}
}
}
// The example displays the following output:
// Cannot parse a null string.
// Cannot parse ''.
// 'True' --> True
// 'False' --> False
// 'true' --> True
// 'false' --> False
// ' true ' --> True
// Cannot parse '0'.
// Cannot parse '1'.
// Cannot parse '-1'.
// Cannot parse 'string'.
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.