Nodejs Utililty Methods Array Index

Array.prototype.indexOf = function(given, strict) {
  var result = null;
  this.each(function(elem, idx) {
    if (strict) {
      if (elem === given) {
        result = idx;
        return false;
    else {
      if (elem == given) {
        result = idx;
        return false;
  })
  return result;

Array.prototype.indexOf = function(item){
  for (var i = 0; i < this.length; i++) {
    if(this[i] === item) return i;
  };
  return -1;
};

Array.prototype.indexOf = function(item){
  var index = -1;
  for (var i=0; i<this.length; i++){
    if (this[i] === item){
      index = i;
      break;
  return index;
...

if(!Array.indexOf) {
Array.prototype.indexOf = function(item,from)
  if(!from)
    from = 0;
  for(var i=from; i<this.length; i++) {
    if(this[i] === item)
      return i;
  return -1;
};}

Array.prototype.indexOf = Array.indexOf || function(needle) {
  for(var i = 0; i < this.length; i++) {
    if(this[i] == needle) {
      return i;
  return -1;
};

Array.prototype.indexOf = function(o){
  for(var i = 0, len = this.length; i < len; i++){
    if(this[i] === o){
      return i;
};

Array.prototype.indexOf = function(obj) {
  for (var i = 0; i < this.length; i++) {
    if (this[i] == obj)
      return i;
  return -1;
};

Array.prototype.indexOf = function (obj) {
    for (var i = 0; i < this.length; i++) {
        if (this[i] == obj) {
            return i;
    return -1;
};

Array.prototype.indexOf = function (obj) {
    for (i = 0; i < this.length; i++) {
  if (obj === this[i]) {
      return i
    return -1;
};

Array.prototype.indexOf = function(obj){
  var l = this.length;
  for(var i=0; i<l; i++){
    if(this[i] == obj){
      return i;
  return -1;
};
...