Editing array filter speeds 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="http://sjhcockrell.s3.amazonaws.com/downloads/belt.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.4.3/underscore-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 a = [], b = [], c = []; for (var i = 0; i < 30; i+=1) { a.push(i); } for (var i = 0; i < 1000; i+=1) { b.push(i*2); } for (var i = 0; i < 1000; i+=1) { c.push(i*3); } var slice = Array.prototype.slice, concat = Array.prototype.concat; function ix_filter(a) { var c = [], len = a.length >>> 0, i = -1, to_subtract = B.native_concat.apply(B.ArrayInstance, arguments); while (len > (i += 1)) { a_i = a[i]; B.indexOf(to_subtract, a_i, len) === -1 && c.push(a_i); } return c; } function native_filter(a) { var to_subtract = B.native_concat.apply(B.ArrayInstance, B.native_slice.call(arguments, 1)); return a.filter(function(value) { return B.indexOf(to_subtract, value) === -1; }); } function native_filter_plus_underscore(a) { var rest = concat.apply(B.ArrayInstance, slice.call(arguments, 1)); return _.filter(a, function(value) { return !_.contains(rest, value); }); } 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 ix_filter(a, b); Test 2 Title Async (check if this is an asynchronous test) Code native_filter(a, b); Test 3 Title Async (check if this is an asynchronous test) Code native_filter_plus_underscore(a, b); Test 4 Title Async (check if this is an asynchronous test) Code _.difference(a,b);