Char.IsNumber Method (Char) (System)

IsNumber Method (Char)

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Char..::.IsNumber Method (Char)

Updated: November 2007

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

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

Syntax

Visual Basic (Declaration)

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

Visual Basic (Usage)

Dim c As Char
Dim returnValue As Boolean

returnValue = Char.IsNumber(c)

public static bool IsNumber(
    char c
)

Visual C++

public:
static bool IsNumber(
    wchar_t c
)

public static boolean IsNumber(
    char c
)

JScript

public static function IsNumber(
    c : char
) : boolean

Parameters

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

Return Value

Type: System..::.Boolean

true if c is a number; otherwise, false.

Remarks

This method determines if a Char is of any numeric Unicode category. This contrasts with IsDigit, which determines if a Char is a radix-10 digit.

Valid numbers are members of the following categories in UnicodeCategory: DecimalDigitNumber, LetterNumber, or OtherNumber.

Examples

The following code example demonstrates IsNumber.

Visual Basic

Imports System

Module IsNumberSample

    Sub Main()

        Dim str As String
        str = "non-numeric"

        Console.WriteLine(Char.IsNumber("8"c))      ' Output: "True"
        Console.WriteLine(Char.IsNumber(str, 3))    ' Output: "False"

    End Sub

End Module

using System;

public class IsNumberSample {
    public static void Main() {
        string str = "non-numeric";

        Console.WriteLine(Char.IsNumber('8'));        // Output: "True"
        Console.WriteLine(Char.IsNumber(str, 3));    // Output: "False"
    }
}

Visual C++

using namespace System;
int main()
{
   String^ str =  "non-numeric";
   Console::WriteLine( Char::IsNumber( '8' ) ); // Output: "True"
   Console::WriteLine( Char::IsNumber( str, 3 ) ); // Output: "False"
}

import System.*;

public class IsNumberSample
{
    public static void main(String[] args)
    {
        String str = "non-numeric";

        Console.WriteLine(Char.IsNumber('8'));        // Output: "True"
        Console.WriteLine(Char.IsNumber(str, 3));    // Output: "False"
    } //main
} //IsNumberSample

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, 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

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.

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