How to test if an input value = char A Z in C#

 while (asteriskWord != hangCharacters && score < 5)
 {               
      while ( letter != ) //This is where I want to test for A-Z a-z
      { 
          Console.WriteLine("Enter a letter please");
          letter = Convert.ToChar(Console.ReadLine());
      }
 }

After the first while-loop I want to be able to place the input inside of a while loop that breaks if the value is = letters A-Z or a-z.

This is so that if the user enters the wrong information, the loop will continue to ask for the information.

Thank you for your time and consideration. Also I tried doing letter != 'A' && letter != 'a'...... and so on, but it didn't work for some reason.

Jon Skeet
people
quotationmark

Well the simplest way would be to just use comparisons. If you definitely want to do it in a single expression, Glorfindel's answer is appropriate. However, all those brackets and the negation makes me nervous of the readability. I'd break it into a separate method:

while (!IsValidLetter(letter))
{
    ...
}

...

private static bool IsValidLetter(char letter)
{
    return (letter >= 'a' && letter <= 'z') ||
           (letter >= 'A' && letter <= 'Z');
}

Whichever you find more readable - the latter is easier to modify later, of course, if you end up with more complicated requirements.

people

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