#   
## Overview
A character can be an alphabet, symbol, etc. In other words, a character can be alphanumeric. In C#, we can use the **`IsDigit()`** method to check if a character is numeric or a digit.

The `IsDigit()` method can be used on a single character or on a string. In the case of a string, we have to specify the index position of the character in the string.

`IsDigit()` returns `true` if the character is a decimal digit; otherwise, it returns `false`.

## Syntax
```c#
// on  character
IsDigit(Char)
// on a string
IsDigit(String, int32)
```

## Parameters
* `Char`: The character we want to check.

* `String`: The string that we want to check to see if any character at index position `int32` is a digit.

* `int32`: The index position of the character in a string we want to check.

## Code example
In the example below, we create some strings and characters and see if certain characters are decimal digits or not.




// use system
using System;
// create class
class DigitChecker
{
    static void Main()
    {
      // create characters
      char char1 = '5';
      char char2 = 'p';

      // create strings
      string str1 = "1234";
      string str2 = "hi";

      // check characters
      bool a = Char.IsDigit(char1);
      bool b = Char.IsDigit(char2);
      bool c = Char.IsDigit(str1, 2);   // position 3
      bool d = Char.IsDigit(str2, 0);    // position 1

      // print out returned values
      System.Console.WriteLine(a);
      System.Console.WriteLine(b);
      System.Console.WriteLine(c);
      System.Console.WriteLine(d);
    }
}

#    
## Explanation
In the code above, *line 17* and *line 19* return `true` because the value of `char1`, which is `5`, is actually a numeric value/digit. `str1` has `3` at position 3, which is also a number.

The other lines return `false` because the values are not decimal digits.

How to check if a character is a digit in C#

Use C#'s IsDigit() method to check if a character is numeric, applicable to single characters or specific string indices.