Check if a string is a palindrome

Question

I have a string as input and have to break the string in two substrings. If the left substring equals the right substring then do some logic.

How can I do this?

Answer 1

Since a palindrome also includes numbers, words, sentences, and any combinations of these, and should ignore punctuation and case, (See Wikipedia Article) I propose this solution:

public class Palindrome
{
    static IList Allowed = new List {
        'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'h',
        'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',
        'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
        '1', '2', '3', '4', '5', '6', '7', '8', '9',
        '0'
    };
    private static int[] GetJustAllowed(string text)
    {
        List characters = new List();
        foreach (var c in text)
             characters.Add(c | 0x20); 

        return characters.Where(c => Allowed.Contains(c)).ToArray();
    }
    public static bool IsPalindrome(string text)
    {
        if(text == null || text.Length == 1)
             return true;

        int[] chars = GetJustAllowed(text);
        var length = chars.Length;

        while (length > 0)
            if (chars[chars.Length - length] != chars[--length])
                return false;

        return true;
    }
    public static bool IsPalindrome(int number)
    {
        return IsPalindrome(number.ToString());
    }
    public static bool IsPalindrome(double number)
    {
        return IsPalindrome(number.ToString());
    }
    public static bool IsPalindrome(decimal number)
    {
        return IsPalindrome(number.ToString());
    }

}