Char.IsDigit Method

Definition

Namespace:

System

Assembly:

System.Runtime.dll

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

Overloads

IsDigit(Char)	Indicates whether the specified Unicode character is categorized as a decimal digit.
IsDigit(String, Int32)	Indicates whether the character at the specified position in a specified string is categorized as a decimal digit.

Examples

The following code example demonstrates IsDigit.

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

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"
    }
}

open System

let ch = '8'

printfn $"{Char.IsDigit ch}"                        // Output: "True"
printfn $"""{Char.IsDigit("sample string", 7)}"""   // Output: "False"

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

Remarks

Valid digits are members of the UnicodeCategory.DecimalDigitNumber category.

IsDigit(Char)

Source:

Char.cs

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

public:
 static bool IsDigit(char c);

public static bool IsDigit (char c);

static member IsDigit : char -> bool

Public Shared Function IsDigit (c As Char) As Boolean

Parameters

c

Char

The Unicode character to evaluate.

Returns

Boolean

true if c is a decimal digit; otherwise, false.

Remarks

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.

Valid digits are members of the UnicodeCategory.DecimalDigitNumber category.

See also

• IsDigit(Rune)
• Boolean
• IsNumber(Char)

IsDigit(String, Int32)

Source:

Char.cs

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

public:
 static bool IsDigit(System::String ^ s, int index);

public static bool IsDigit (string s, int index);

static member IsDigit : string * int -> bool

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

Parameters

s

String

A string.

index

Int32

The position of the character to evaluate in s.

Returns

Boolean

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

Exceptions

ArgumentNullException

s is null.

ArgumentOutOfRangeException

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

Remarks

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.

See also

• Boolean
• IsNumber(Char)