Nodejs Utililty Methods String Palindrome Check

String.prototype.palindrome = function() {
  var palindrome = ["forwards", "backwards"];
  for (var i = 0; i < palindrome.length; i++) {
    var index = this.indexOf(palindrome[i]);
    if(index >= 0) {
      return true;
  return false;
...

String.prototype.palindrome = function() {
  var len = this.length-1;
  for (var i = 0; i <= len; i++) {
    if (this.charAt(i) !== this.charAt(len-i)) {
      return false;
    if (i === (len-i)) {
      return true;
  return true;
};
String.prototype.palindromeAdv = function() {
  var r = this.split("").reverse().join("");
  return (r === this.valueOf());
var phrases = ["eve",
               "kayak",
               "mom",
               "wow",
               "noon",
               "Not a palindrome"];
for (var i = 0; i < phrases.length; i++) {
  var phrase = phrases[i];
  if (phrase.palindrome()) {
    console.log("'" + phrase + "' is a palindrome");
  } else {
    console.log("'" + phrase + "' is NOT a palindrome");

String.prototype.palindrome = function() {
    for (var i = 0; i <= this.length - 1; i++) {
        if (this.charAt(i) !== this.charAt(len - i)) {
            return false;
        if (i === (len - i)) {
            return true;
    return true;
};
String.prototype.palindromeAdv = function() {
    var r = this.split("").reverse().join("");
    return (r === this.valueOf());
};

'use strict';
String.prototype.palindrome = String.prototype.palindrome || function ( ) {
  if ( typeof this == 'string' ) {
    return this === this.split('').reverse().join('');
  else {
    return false;
};
...

String.prototype.palindrome = function(loose) {
    var str = loose ? this.replace(/[^a-zA-Z0-9]+/gi, '').toLowerCase() : this;
    return str == str.split('').reverse().join('');

function palindrome(str) {
  str = str.replace(/[^a-zA-Z0-9]+/gi, '').toLowerCase();
    return str == str.split('').reverse().join('');
palindrome("eye");

function palindrome(str) {
  var removeChar = str.replace(/[^A-Z0-9]/ig, "").toLowerCase();
  var checkPalindrome = removeChar.split('').reverse().join('');
   return (removeChar === checkPalindrome);
palindrome("eye");

String.prototype.reverse = function(){ return this.split("").reverse().join(""); }
function palindrome(str) { return str == str.reverse(); }
console.log(palindrome("ingirumimusnocteetconsumimurigni"));

String.prototype.isPalindrome = function() {
  var str = this;
  var half = parseInt(str.length / 2, 10);
  for (var i = 0, last = str.length - 1; i < half; ++i) {
    if (str[i] != str[last - i]) return false;
  return true;
};

String.prototype.isPalindrome=function(){
  var palavra=this;
  for(var i=0;i<palavra.length/2;i++){
    if(palavra[i]!=palavra[palavra.length-1-i]){
      return false;
  return true;