Editing Arrays jQuery.merge vs concat 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) Merge creates a smaller footprint because it loops through the original array and adds the new items. Concat is a built-in Javascript function and should be faster, but has a larger footprint. 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> <script> //unmodified array var baseArray2 = ["Napoleon"]; var baseArray; //modified arrays var catArray = merArray = []; //cache concat prototype for best performance var concat = Array.prototype.concat; </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) 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 catArray = concat.call(catArray, baseArray); Test 2 Title Async (check if this is an asynchronous test) Code $.merge(merArray, baseArray);