Speed Up Your JavaScript

Google Tech Talk
June 4, 2009

ABSTRACT

Web Exponents: Speed Up Your JavaScript
Presented by Nicholas C. Zakas.

As an interpreted language, JavaScript is filled with hidden performance issues that conspire to slow down your code and ruin the user experience. Learn exactly what is fast, what is slow, and what you can do to squeeze that last bit of performance out of your JavaScript code.

Nicholas C. Zakas is the author of Professional JavaScript for Web Developers, 2nd Edition (Wrox, 2009), co-author of Professional Ajax, 2nd Edition (Wrox, 2007), and a contributor to Even Faster Web Sites (O'Reilly, 2009). Nicholas is principal front end engineer for the Yahoo! homepage and is also a contributor to the Yahoo! User Interface (YUI) library.

The Web Exponents Series is hosted by Steve Souders

• Category

  Science & Technology

[nathan87]

i laughed at THE DOM too! humourless google employees...

[keemor]

Very pragmatic presentation, real situations with solutions which are measured and tested. Nicholas Zakas is a great speaker for me. Thank you for sharing your knowledge!

[Sudeep Makwana]

You R One Of Best @Zakas.... i m your Fan ....

[aliancemd]

That's the thing. Now with JIT compilers, how relevant is this?

The DOM thing for sure didn't change but the rest...

For example, the depth navigation should not be a problem with a compiler now...

I am interested too...

[Hex72]

Awesome talk, a great insight into the caveats of JavaScript. I have so many loops to optimise in my game now...

[Steph Vandenbussche]

How much of this is still relevant with the latest JS engines? (Chrome 26, IE10, FF19...)

[Charles Phillips]

I knew about scope chain and the need to always declare var to stay local (otherwise it becomes a global variable and that's SLOW [not to mention being at greater risk of collision!]), but there's a LOT in this that I never knew about!

[HuskerSeaofRed]

Ssssssuper Nova.

[s3340985]

Great suggestions for the loops! Would've never thought to flip them if it wasn't for this presentation

[Vic Vlasenko]

good job.

51:30

if there are a lot of global variables (I saw >200 in some apps) it works 2-3 times faster, when grouping them into an object