Char.IsDigit Method (Char) (System)

.NET Framework Class Library

Char..::.IsDigit Method (Char)

Updated: October 2008

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

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

Syntax

Visual Basic (Declaration)

Public Shared Function IsDigit ( _
    c As Char _
) As Boolean

Visual Basic (Usage)

Dim c As Char
Dim returnValue As Boolean

returnValue = Char.IsDigit(c)

public static bool IsDigit(
    char c
)

Visual C++

public:
static bool IsDigit(
    wchar_t c
)

JScript

public static function IsDigit(
    c : char
) : boolean

Parameters

c: Type: System..::.Char
A Unicode character.

Return Value

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

Remarks

This method determines if a Char is a radix-10 digit. This contrasts with the IsNumber method, which determines if a Char is of any numeric Unicode category. Numbers include characters such as fractions, subscripts, superscripts, Roman numerals, currency numerators, encircled numbers, and script-specific digits.

Valid digits are members of the UnicodeCategory..::.DecimalDigitNumber category.

Examples

The following code example demonstrates IsDigit.

Visual Basic

Imports System

Module IsDigitSample

    Sub Main()

        Dim ch8 As Char
        ch8 = "8"c

        Console.WriteLine(Char.IsDigit(ch8))                    ' Output: "True"
        Console.WriteLine(Char.IsDigit("sample string", 6))     ' Output: "False"

    End Sub

End Module

using System;

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

        Console.WriteLine(Char.IsDigit(ch));                    // Output: "True"
        Console.WriteLine(Char.IsDigit("sample string", 7));    // Output: "False"
    }
}

Visual C++

using namespace System;
int main()
{
   char ch = '8';
   Console::WriteLine( Char::IsDigit( ch ) ); // Output: "True"
   Console::WriteLine( Char::IsDigit(  "sample string", 7 ) ); // Output: "False"
}

Platforms

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.

Version Information