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Char.IsLetterOrDigit Method

Definition

Namespace:
System
Assemblies:
mscorlib.dll, System.Runtime.dll
Assemblies:
netstandard.dll, System.Runtime.dll
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

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

Overloads

Name Description
IsLetterOrDigit(String, Int32)

Indicates whether the character at the specified position in a specified string is categorized as a letter or a decimal digit.
IsLetterOrDigit(Char)

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

Examples

The following code example demonstrates IsLetterOrDigit.

using System;

public class IsLetterOrDigitSample {
 public static void Main() {
 string str = "newline:\n";

 Console.WriteLine(Char.IsLetterOrDigit('8'));		// Output: "True"
 Console.WriteLine(Char.IsLetterOrDigit(str, 8));	// Output: "False", because it's a newline
 }
}

open System

let str = "newline:\n"

printfn $"{Char.IsLetterOrDigit '8'}" // Output: "True"
printfn $"{Char.IsLetterOrDigit(str, 8)}" // Output: "False", because it's a newline

Module IsLetterOrDigitSample

 Sub Main()

 Dim str As String
 str = "newline:" + Environment.NewLine

 Console.WriteLine(Char.IsLetterOrDigit("8"c)) ' Output: "True"
 Console.WriteLine(Char.IsLetterOrDigit(str, 8)) ' Output: "False", because it's a NewLine

 End Sub

End Module

Remarks

Valid letters and decimal digits are members of the following categories in UnicodeCategory: UppercaseLetter, LowercaseLetter, TitlecaseLetter, ModifierLetter, OtherLetter, or DecimalDigitNumber.

IsLetterOrDigit(String, Int32)

Source:
Char.cs
Source:
Char.cs
Source:
Char.cs
Source:
Char.cs
Source:
Char.cs

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

public:
 static bool IsLetterOrDigit(System::String ^ s, int index);
public static bool IsLetterOrDigit(string s, int index);
static member IsLetterOrDigit : string * int -> bool
Public Shared Function IsLetterOrDigit (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

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

Exceptions

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

Remarks

Character positions in a string are indexed starting from zero.

Valid letters and decimal digits are members of the following categories in UnicodeCategory: UppercaseLetter, LowercaseLetter, TitlecaseLetter, ModifierLetter, OtherLetter, or DecimalDigitNumber.

See also

Applies to

IsLetterOrDigit(Char)

Source:
Char.cs
Source:
Char.cs
Source:
Char.cs
Source:
Char.cs
Source:
Char.cs

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

public:
 static bool IsLetterOrDigit(char c);
public static bool IsLetterOrDigit(char c);
static member IsLetterOrDigit : char -> bool
Public Shared Function IsLetterOrDigit (c As Char) As Boolean

Parameters

c
Char

The Unicode character to evaluate.

Returns

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

Remarks

Valid letters and decimal digits are members of the following categories in UnicodeCategory: UppercaseLetter, LowercaseLetter, TitlecaseLetter, ModifierLetter, OtherLetter, or DecimalDigitNumber.

See also

Applies to

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