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Char.IsLetter Method (Char)

Updated: May 2009

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

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

public static bool IsLetter(
	char c


Type: System.Char

The Unicode character to evaluate.

Return Value

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

This method determines whether a Char is a member of any category of Unicode letter. Unicode letters include the following:

  • Uppercase letters, such as U+0041 (LATIN CAPITAL LETTER A) through U+005A (LATIN CAPITAL LETTER Z), or U+0400 (CYRILLIC CAPITAL LETTER IE WITH GRAVE) through U+042F (CYRILLIC CAPITAL LETTER YA). These characters are members of the UnicodeCategory.UppercaseLetter category.

  • Lowercase letters, such as U+0061 (LATIN SMALL LETTER A) through U+007A (LATIN SMALL LETTER Z), or U+03AC (GREEK SMALL LETTER ALPHA WITH TONOS) through U+03CE (GREEK SMALL LETTER OMEGA WITH TONOS). These characters are members of the UnicodeCategory.LowercaseLetter category.

  • Title case letters, such as U+01C5 (LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON) or U+1FFC (GREEK CAPITAL LETTER OMEGA WITH PROSGEGRAMMENI). These characters are members of the UnicodeCategory.TitlecaseLetter category.

  • Modifiers, such as U+02B0 (MODIFIER LETTER SMALL H) through U+02C1 (MODIFIER LETTER REVERSED GLOTTAL STOP), or U+1D2C (MODIFIER LETTER CAPITAL A) through U+1D61 (MODIFIER LETTER SMALL CHI). These characters are members of the UnicodeCategory.ModifierLetter category.

  • Other letters, such as U+05D0 (HEBREW LETTER ALEF) through U+05EA (HEBREW LETTER TAV), U+0621 (ARABIC LETTER HAMZA) through U+063A (ARABIC LETTER GHAIN), or U+4E00 (<CJK Ideograph, First>) through U+9FC3 (<CJK Ideograph, Last>). These characters are members of the UnicodeCategory.OtherLetter category.

The following code example demonstrates IsLetter.

using System;

public class IsLetterSample {
	public static void Main() {
		char ch = '8';

		Console.WriteLine(Char.IsLetter(ch));					// False
		Console.WriteLine(Char.IsLetter("sample string", 7));	// True

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0




May 2009

Modified the method description and expanded the Remarks section.

Customer feedback.