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Boolean.TryParse Method

Updated: October 2010

Tries to convert the specified string representation of a logical value to its Boolean equivalent. A return value indicates whether the conversion succeeded or failed.

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

public static bool TryParse(
	string value,
	out bool result
)

Parameters

value
Type: System.String
A string containing the value to convert.
result
Type: System.Boolean%
When this method returns, if the conversion succeeded, contains true if value is equivalent to TrueString or false if value is equivalent to FalseString. If the conversion failed, contains false. The conversion fails if value is null or is not equivalent to either the TrueString or FalseString field.

Return Value

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

The TryParse method is like the Parse method, except the TryParse method does not throw an exception if the conversion fails.

The value parameter can be preceded or followed by white space. The comparison is case-insensitive.

The following example calls the TryParse 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.


using System;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      string[] values = { null, String.Empty, "True", "False", 
                          "true", "false", "    true    ", "0", 
                          "1", "-1", "string" };
      foreach (var value in values)
      {
         bool flag;
         if (Boolean.TryParse(value, out flag))
            outputBlock.Text += String.Format("'{0}' --> {1}", value, flag) + "\n";
         else
            outputBlock.Text += String.Format("Unable to parse '{0}'.",
                              value == null ? "<null>" : value) + "\n";
      }
   }
}
// The example displays the following output:
//       Unable to parse '<null>'.
//       Unable to parse ''.
//       'True' --> True
//       'False' --> False
//       'true' --> True
//       'false' --> False
//       '    true    ' --> True
//       Unable to parse '0'.
//       Unable to parse '1'.
//       Unable to parse '-1'.
//       Unable to parse 'string'.


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Date

History

Reason

October 2010

Replaced the example.

Customer feedback.

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