Nodejs Utililty Methods Array Contain

Array.prototype.contains = function (array) {
    var debug = true;
    var starts = [];
    for (var i = 0; i < this.length; i++) {
  if (this[i] == array[0])
      starts.push(i);
    console.log('found', starts.length, 'possible matches');
    for (var p = 0; p < starts.length; p++) {
...

var fs =require('fs');
var lineReader = require('line-reader');
Array.prototype.contains = function (array, sizediff) {
    if (!array)
        return false;
    if (this.length <= array.length)
        return false;
  if (sizediff && this.length > array.length + sizediff)
    return false;
...

Array.prototype.contains = function (e) {
    return this.indexOf(e) > -1;
};

Array.prototype.contains = function(e) {
    for (var i = this.length - 1; i >= 0; i--) {
        if (this[i] == e) {
            return true;
    return false;
};

Array.prototype.contains  = function(e,ignore)  {  
  if(ignore==undefined) ignore = false;
    for(var i=0;i<this.length;i++){  
    if(ignore){
      if(this[i].toLowerCase() == e.toLowerCase()) 
        return true; 
    }else{
      if(this[i] == e) 
        return true; 
...

"use strict";
Array.prototype.contains = function(el){
  return this.indexOf(el) > -1;
};
var rotateArray = function rotateArray(arr){ 
  arr.unshift(arr.pop());
  return arr;
};
print(function(input){ 
...

Array.prototype.contains = function(el) {
  for(var i = 0; i < this.length; i++) {
    if(this[i] === el) {
      return true;
  return false;
};

Array.prototype.contains = function(el, test) {
    if (test == null) return this.indexOf(el) >= 0;
    for (var i = this.length; --i >= 0;) if (test(this[i], el)) return true;
};

Array.prototype.contains = function(ele) {
  for (var i = 0; i < this.length; i++) {
    if (this[i] === ele) return true;
  return false;
};
Array.prototype.clear = function() {
  var cnt = this.length;
  this.splice(0, cnt);
...

Array.prototype.contains = function(ele)
    if(!ele) return false;
    var b=false;
    for(var i=0;i<this.length;i++){
        if(this[i]==ele){
            b=true;
    return b;
};
Array.prototype.uniq = function(){
    var a = [];
    this.forEach(function(b){ 
        if(a.indexOf(b) < 0)
            {a[a.length] = b}
    });
    return a;
};
Array.prototype.uniqById = function(){
    var a = [];
    var r = [];
    this.forEach(function(b){
        if(b){
            if("id" in b){
                if(a.indexOf(b.id) < 0){
                    a[a.length] = b.id;
                    r[r.length] = b;
            }else if("_id" in b){
                if(a.indexOf(b._id) < 0){
                    a[a.length] = b._id;
                    r[r.length] = b;
    });
    return r;