Comments on: Zakas’ JavaScript performance tips

By: Peter Moss

Peter Moss — Wed, 17 Mar 2010 22:23:48 +0000

I don’t see anything new in his list. The things that he is recommending are general optimizations that one should be using regardless of language.

By: Ben Cherry

Ben Cherry — Fri, 19 Feb 2010 21:24:02 +0000

Sorry for bumping an older post, but if you do `var jQuery = jQuery;` you’ll find that jQuery === undefined, because you’ve now scoped jQuery to your function, initialized with undefined first, then it gets assigned to jQuery, which is already undefined. You should do `var $ = jQuery;`, or another different name. Or even better, import it in the function arguments:

(function (jQuery) {…}(jQuery));

Anyways, otherwise good concise tips! And, obviously thanks to Zakas too! Sad to get an email from Amazon this morning that my pre-order of your book is getting pushed back to April 🙁

By: Brendan Kidwell

Brendan Kidwell — Thu, 13 Aug 2009 03:07:18 +0000

Thanks! I subscribed to your blog some time ago for some reason that I forget. If I hadn’t, I wouldn’t have seen this Google Tech Talk video you posted. I’m so glad that I DID see it! I was able have one more go at optimizing this horrible in-house form I have, and I shaved off about 4 more seconds from the initialization.

By: Mark McDonnell

Mark McDonnell — Mon, 10 Aug 2009 08:04:14 +0000

As Ryan mentioned there is a book (almost in final release) by Thomas Fuchs which I have bought/downloaded – you can find out more from the website http://javascriptrocks.com/performance/

I personally found it very detailed and definitely worth the price, but depending on your skill level you may not need it (although it was so detailed and covered so much ground – not just code optimization – that I think even hardened JavaScript will get something out of it).

By: Nicholas C. Zakas

Nicholas C. Zakas — Mon, 10 Aug 2009 01:51:40 +0000

I’m glad you enjoyed the presentation. I have a large amount of performance-related posts on my site that I hope you’ll check out as well. And one last point: I’m finishing up a book strictly on JavaScript performance that covers all of my best practices and more.

By: Jani Hartikainen

Jani Hartikainen — Sun, 09 Aug 2009 12:50:14 +0000

Some of these optimizations like the reverse loop won’t really affect things a lot, and they will just make your code more difficult to read.

Nevertheless, if you really want to know some more confusing tricks to speed up JS code, I wrote a post about some obscure ones here: http://codeutopia.net/blog/2009/04/30/optimizing-javascript-for-extreme-performance-and-low-memory-consumption/

By: Cloud Lin

Cloud Lin — Sun, 09 Aug 2009 10:03:48 +0000

It`s a useful knowledge.
Thanks for your share.

By: Ryan Townsend

Ryan Townsend — Sat, 08 Aug 2009 14:26:54 +0000

Amy Hoy (rails dev @ slash7) & Thomas Fuchs (scriptaculous) are writing an e-book on JavaScript performance (it currently stands at some 282 pages) that should be in full release soon, she has a discount of $5 (and says she’s likely to put the full-price up after release – because $29 is a bargain for that much material) so grab it asap @ jsrocks.com

I’m not affiliated with them, just thought you’d be interested.