Char.IsHex() in C#

Question

Following on from this question what would be the best way to write a Char.IsHex() function in C#. So far I've got this but don't like it:

bool CharIsHex(char c) {
    c = Char.ToLower(c);
    return (Char.IsDigit(c) || c == 'a' || c == 'b' || c == 'c' || c == 'd' || c == 'e' || c == 'f')
}

Answer 1

You can write it as an extension method:

public static class Extensions
{
   public static bool IsHex(this char c)
   {
      return   (c >= '0' && c <= '9') ||
               (c >= 'a' && c <= 'f') ||
               (c >= 'A' && c <= 'F');
   }
}

This means you can then call it as though it were a member of char.

char c = 'A';

if (c.IsHex())
{
   Console.WriteLine("We have a hex char.");
}

Answer 2

From my answer to the question you linked to:

bool is_hex_char = (c >= '0' && c <= '9') ||
                   (c >= 'a' && c <= 'f') ||
                   (c >= 'A' && c <= 'F');