Char.GetNumericValue() Method in C#

The Char.GetNumericValue() method in C# converts a specified Unicode character to its corresponding numeric value as a double. This method is particularly useful when working with Unicode digits from various scripts and numeral systems.

Syntax

Following is the syntax for the Char.GetNumericValue() method −

public static double GetNumericValue(char ch);

Parameters

• ch − A Unicode character to convert to its numeric value.

Return Value

The method returns a double representing the numeric value of the character. If the character does not represent a numeric digit, it returns -1.

Using GetNumericValue() with Digit Characters

Example

using System;

public class Demo {
   public static void Main() {
      char val = '5';
      Console.WriteLine("Character: " + val);
      Console.WriteLine("Numeric Value: " + Char.GetNumericValue(val));
      
      // Testing with different numeric characters
      char[] digits = {'0', '3', '7', '9'};
      
      foreach (char digit in digits) {
         Console.WriteLine("'" + digit + "' ? " + Char.GetNumericValue(digit));
      }
   }
}

The output of the above code is −

Character: 5
Numeric Value: 5
'0' ? 0
'3' ? 3
'7' ? 7
'9' ? 9

Using GetNumericValue() with Non-Numeric Characters

Example

using System;

public class Demo {
   public static void Main() {
      char val = 'm';
      Console.WriteLine("Character: " + val);
      Console.WriteLine("Numeric Value: " + Char.GetNumericValue(val));
      
      // Testing with various non-numeric characters
      char[] nonDigits = {'a', 'Z', '@', '#'};
      
      foreach (char ch in nonDigits) {
         Console.WriteLine("'" + ch + "' ? " + Char.GetNumericValue(ch));
      }
   }
}

The output of the above code is −

Character: m
Numeric Value: -1
'a' ? -1
'Z' ? -1
'@' ? -1
'#' ? -1

Using GetNumericValue() with Unicode Digits

Example

using System;

public class Demo {
   public static void Main() {
      // Arabic-Indic digits
      char arabicFive = '\u06F5';  // ?
      char arabicTwo = '\u06F2';   // ?
      
      Console.WriteLine("Arabic digit ?: " + Char.GetNumericValue(arabicFive));
      Console.WriteLine("Arabic digit ?: " + Char.GetNumericValue(arabicTwo));
      
      // Roman numerals
      char romanV = '\u2164';  // ? (Roman numeral five)
      Console.WriteLine("Roman numeral ?: " + Char.GetNumericValue(romanV));
      
      // Regular ASCII digits for comparison
      Console.WriteLine("ASCII digit '8': " + Char.GetNumericValue('8'));
   }
}

The output of the above code is −

Arabic digit ?: 5
Arabic digit ?: 2
Roman numeral ?: 5
ASCII digit '8': 8

Common Use Cases

• Input validation − Check if user input contains valid numeric characters

• String parsing − Extract numeric values from mixed character strings

• Unicode processing − Handle numeric characters from different languages and scripts

Conclusion

The Char.GetNumericValue() method provides a reliable way to convert Unicode characters to their numeric values, returning the corresponding double value for digits or -1 for non-numeric characters. It supports various Unicode numeral systems, making it useful for international applications.