Editing grep vs pure js This edit will create a new revision. Your details (optional) Name Email (won’t be displayed; might be used for Gravatar) URL Test case details Title * Published (uncheck if you want to fiddle around before making the page public) Description (in case you feel further explanation is needed)(Markdown syntax is allowed) Are you a spammer? (just answer the question) Preparation code Preparation code HTML (this will be inserted in the <body> of a valid HTML5 document in standards mode) (useful when testing DOM operations or including libraries) <script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script> Include JavaScript libraries as follows: <script src="//cdn.ext/library.js"></script> Define setup for all tests (variables, functions, arrays or other objects that will be used in the tests) (runs before each clocked test loop, outside of the timed code region) (e.g. define local test variables, reset global variables, clear canvas, etc.) (see FAQ) var me = {boards: [{id: 1}, {id:2}, {id:3}, {id:4}, {id:5}, {id:6}, {id:7}, {id:8}, {id:9}, {id:10}]}; var id = 10; function cond(e){return e.id == id} Array.prototype.filter1 = function(fun /*, thisp */) { "use strict"; if (this == null) throw new TypeError(); var t = Object(this); var len = t.length >>> 0; if (typeof fun != "function") throw new TypeError(); var res = []; var thisp = arguments[1]; for (var i = 0; i < len; i++) { if (i in t) { var val = t[i]; // in case fun mutates this if (fun.call(thisp, val, i, t)) res.push(val); } } return res; }; Define teardown for all tests (runs after each clocked test loop, outside of the timed code region) (see FAQ) Code snippets to compare Test 1 Title Async (check if this is an asynchronous test) Code $.grep(me.boards, cond); Test 2 Title Async (check if this is an asynchronous test) Code me.boards.filter1(cond); Test 3 Title Async (check if this is an asynchronous test) Code me.boards.filter(cond);