IsDigit Method (String, Int32)
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Char.IsDigit Method (String, Int32)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

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 static bool IsDigit(
	string s,
	int index
)

Parameters

s
Type: System.String
A String.
index
Type: System.Int32
The character position in s.

Return Value

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

ExceptionCondition
ArgumentNullException

s is null.

ArgumentOutOfRangeException

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

This method determines if a Char is a radix-10 digit. This contrasts with IsNumber, which determines if 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 example demonstrates IsDigit.


using System;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      char ch = '8';

      outputBlock.Text += Char.IsDigit(ch) + "\n";			// Output: "True"
      outputBlock.Text += Char.IsDigit("sample string", 7) + "\n";	// Output: "False"
   }
}


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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