C# Palindrome Test

Question

I need to create a IsPalindrome function where it will determine if a provided string is a palindrome. Alphanumeric chars will be considered when evaluating whether or not the string is a palindrome. With this said, I am having trouble trying to disreguard the spaces and the Caps. Here is what my function looks like now. If this makes a difference: After this function is done I will then have to have parse a JSON file and have each element in the "strings" array, into the IsPalindrome function. Any tips?

 private static bool IsPalindrome(string value)
    {
        var min = 0;
        var max = value.Length - 1;

        while (true)
        {
            if (min > max)
                return true;
            var a = value[min];
            var b = value[max];

            if (if (char.ToLower(a) == char.ToLower(b))
             {
              return true;
             }
              else {
                 return false;
              }

            min++;
            max--;
        }

Answer 1

The way I'd do this is to turn the string into an array of characters, skipping non-letter characters, and making all the characters lowercase. Then, I'd use an index to check if the first half of the array is equal to the last. Something like this:

public static bool IsPalindrome(string value)
{
    char[] forwards = (from c in value.ToLower().ToCharArray() where char.IsLetter(c) select c).ToArray();
    int middle = (forwards.Length / 2) + 1;
    for (int i = 0; i < middle; i++)
        if (forwards[i] != forwards[forwards.Length - 1 - i])
            return false;
    return true;
}

That first line uses LINQ to make the array, so you need a using System.Linq;