How to write palindrome in JavaScript

Question

I wonder how to write palindrome in javascript, where I input different words and program shows if word is palindrome or not. For example word noon is palindrome, while bad

Answer 1

Look at this:

function isPalindrome(word){
    if(word==null || word.length==0){
        // up to you if you want true or false here, don't comment saying you 
        // would put true, I put this check here because of 
        // the following i < Math.ceil(word.length/2) && i< word.length
        return false;
    }
    var lastIndex=Math.ceil(word.length/2);
    for (var i = 0; i < lastIndex  && i< word.length; i++) {
        if (word[i] != word[word.length-1-i]) {
            return false;
        }
     }
     return true;
} 

Edit: now half operation of comparison are performed since I iterate only up to half word to compare it with the last part of the word. Faster for large data!!!

Since the string is an array of char no need to use charAt functions!!!

Reference: http://wiki.answers.com/Q/Javascript_code_for_palindrome