Char.IsNumber Method (Char) (System)

.NET Framework Class Library

Char..::.IsNumber Method (Char)

Updated: October 2008

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
)

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. In addition to digits, numbers include characters, fractions, subscripts, superscripts, Roman numerals, currency numerators, and encircled numbers. This method contrasts with the IsDigit method, which determines if a Char is a radix-10 digit.

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

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"
}

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