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Char.IsNumber Method (String, Int32)

Indicates whether the character at the specified position in a specified string is categorized as a number.

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

public static bool IsNumber (
	string s,
	int index
)
public static boolean IsNumber (
	String s, 
	int index
)
public static function IsNumber (
	s : String, 
	index : int
) : boolean

Parameters

s

A string.

index

The character position in s.

Return Value

true if the character at position index in s is a number; otherwise, false.

Exception typeCondition

ArgumentNullException

s is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

index is less than zero or greater than the last position in s.

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.

Character positions in a string are indexed starting from zero.

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

The following code example demonstrates IsNumber.

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"
	}
}

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

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

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

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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