Kommentare zu: 101 on jQuery Selector Performance

Von: Andreas Grabner

Andreas Grabner — Fri, 18 Nov 2011 11:48:46 +0000

Hi Sandeep

jQuery – at least in newer versions – caches lookup results of previous queries. so – make sure you measures all of your lookups. It could be that this lookup is not the first.

Von: sandeep

sandeep — Fri, 18 Nov 2011 10:08:30 +0000

hi,
I used dynaTrace yesterday, and found 400ms time taken for one selector like $(“#myDiv :text”) in jquery, that was shocked for me.
So I go for manually findout the time taken by function as below

var dt_start = +new Date();
$(“#myDiv :text”).val(“”);
var dt_end = +new Date();
alert(dt_end – dt_start)

As per above code this show me 30ms time take by the jQuery statement.

Please tell me why this difference come.

Von: Ensuring Web Site Performance – Why, What and How to Measure Automated and Accurately « Tech Notes

Mon, 10 Oct 2011 18:37:34 +0000

[...] user. This can very often be seen when expensive CSS Selector Lookups (check out the blogs about jQuery and Prototype CSS Selector Performance) are used or when using dynamic elements like JavaScript [...]

Von: How Case-Sensitivity for ID and ClassName can kill your page load time Application Performance, Scalability and Architecture – The dynaTrace Blog

Tue, 13 Sep 2011 11:52:47 +0000

[...] 5-10ms (times vary depending on number of DOM elements on your page). More on this in our blogs 101 on jQuery Selector Performance or 101 on Prototype CSS [...]

Von: -

Thu, 26 May 2011 09:05:10 +0000

great, thanks!

Von: -

Wed, 25 May 2011 11:51:00 +0000

it would be great to see the same test on more recent version of jquery, thanks a lot for your article

Von: Andreas Grabner

Andreas Grabner — Sat, 16 Oct 2010 08:31:08 +0000

@peng: it is the dynaTrace AJAX Edition. Download it – its free: http://ajax.dynatrace.com

Von: peng

peng — Sat, 16 Oct 2010 08:01:18 +0000

this fo Screenshot tools？？

Von: IE Compatibility View: How to identify performance problems between IE versions Application Performance, Scalability and Architecture – The dynaTrace Blog

Thu, 22 Jul 2010 13:17:15 +0000

[...] on elements identified via their class name or complex lookups with parent->child relations. I wrote an article that explains the performance implications of these lookups and listed other JavaScript/AJAX [...]

Von: How to identify IE Add-Ons such as Skype that impact Web Site Performance Performance, Scalability and Architecture – Java and .NET Application Performance Management (dynaTrace Blog)

Mon, 12 Jul 2010 19:12:42 +0000

[...] Add-Ons like Skype have to iterate through the DOM whenever a page is loaded or modified. The time it takes to iterate the DOM depends on the size of the DOM. That explains why those Add-Ons don’t have the same web site performance impact on every page as it depends on the number of DOM elements. It is a general JavaScript/AJAX Best Practice to limit the number of DOM elements as there are many other implications with large DOM trees, e.g.: Impact on CSS Selector Performance. [...]