Editing ES5 "use strict" Performance 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) What is the performance different for calling a function that has opted in to ES5 Strict Mode? 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) 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 baz = "bat"; function normal() { return Math.random() * (arguments[0] || 1) + baz; } var normalClosure = (function() { "use strict"; var foo = "bar"; return function() { return Math.random() * (arguments[0] || 1) + foo; }; }()); function strict() { "use strict"; return Math.random() * (arguments[0] || 1) + baz; } var strictClosure = (function() { "use strict"; var foo = "bar"; return function() { return Math.random() * (arguments[0] || 1) + foo; }; }()); var strictInStrictClosure = (function() { "use strict"; var foo = "bar"; return function() { "use strict"; return Math.random() * (arguments[0] || 1) + foo; }; }()); // Warm up the JIT: normal(); normalClosure(); strict(); strictClosure(); strictInStrictClosure(); 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 normal(); normal(10); Test 2 Title Async (check if this is an asynchronous test) Code normalClosure(); normalClosure(10); Test 3 Title Async (check if this is an asynchronous test) Code strict(); strict(10); Test 4 Title Async (check if this is an asynchronous test) Code strictClosure(); strictClosure(10); Test 5 Title Async (check if this is an asynchronous test) Code strictInStrictClosure(); strictInStrictClosure(10);