Here you can find the source of contains(item)
// Return whether an entry exists in an array Array.prototype.contains = function(item) { return this.indexOf(item) != -1; };
Array.prototype.contains = function(item) { return this.indexOf(item) === -1 ? false : true
Array.prototype.contains = function (item) { for (i in this) { if (this[i] === item) { return true; return false; };
Array.prototype.contains = function (item) { for (var i=0; i<this.length; ++i) if (this[i] == item) return true; return false; };
Array.prototype.contains = function(item){ for(i=0;i<this.length;i++){ if(this[i]==item){return true;} return false; };
Array.prototype.contains = function (item) { for (var i = 0; i < this.length; i++) { if (this[i] == item) return true; return false; };
Array.prototype.contains = function(item){ var contains = false; for (var i=0; i<this.length; i++){ if (this[i] === item){ contains = true; break; return contains; ...
Array.prototype.contains = function (item, from) { return this.indexOf(item, from) !== -1; };
Array.prototype.contains = function(item, from){ return this.indexOf(item, from) != -1;
Array.prototype.contains = function (k) { 'use strict'; var p; for (p in this) { if (this.hasOwnProperty(p) && this[p] === k) { return true; return false; ...