Char.IsDigit Method (String, Int32)

 

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

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

Public Shared Function IsDigit (
	s As String,
	index As Integer
) As Boolean

Parameters

s
Type: System.String

A string.

index
Type: System.Int32

The position of the character to evaluate in s.

Return Value

Type: System.Boolean

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

Exception Condition
ArgumentNullException

s is null.

ArgumentOutOfRangeException

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

This method determines whether a Char is a radix-10 digit. This contrasts with IsNumber, which determines whether 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.

Character positions in a string are indexed starting from zero.

Valid digits are members of the UnicodeCategory.DecimalDigitNumber category.

The following code example demonstrates IsDigit.

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

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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