Char.IsLetterOrDigit Method (Char)

Indicates whether the specified Unicode character is categorized as a letter or a decimal digit.

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


Public Shared Function IsLetterOrDigit ( _
    c As Char _
) As Boolean
public static bool IsLetterOrDigit(
    char c


  • c
    Type: System.Char
    The Unicode character to evaluate.

Return Value

Type: System.Boolean
true if c is a letter or a decimal digit; otherwise, false.


Valid alphabetic letters and decimal digits are members of the following categories in UnicodeCategory: UppercaseLetter, LowercaseLetter, TitlecaseLetter, ModifierLetter, OtherLetter, or DecimalDigitNumber.


The following example demonstrates IsLetterOrDigit.

Module Example

   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)

      Dim str As String
      str = "newline:" + vbNewLine

      outputBlock.Text &= Char.IsLetterOrDigit("8"c) & vbCrLf       ' Output: "True"
      outputBlock.Text += String.Format(Char.IsLetterOrDigit(str, 8)) & vbCrLf     ' Output: "False", because it's a NewLine

   End Sub

End Module
using System;

public class Example
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
      string str = "newline:\n";

      outputBlock.Text += Char.IsLetterOrDigit('8').ToString() + "\n";  
      outputBlock.Text += (Char.IsLetterOrDigit(str, 8).ToString()) + "\n";
// The example displays the following output:
//    True
//    False

Version Information


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.