Thanks for the answers, guys. I should have done what Ricardo did, and post a small code example.
Using an ID is (probably) always faster than using a class, since it maps to the native JS method getElementById (even though there are browsers which also support getElementsByClassName - http://ejohn.org/blog/getelementsbyclassname-speed-comparison/). But the point here was indeed to compare the performance of the two mentioned selector statements. So special thanks to Ricardo. :) On 1 Jul., 08:56, Ricardo <ricardob...@gmail.com> wrote: > Yes, but in this tree: > > <ul class="nav"> > <li><a href="#"></a></li> > </ul> > > both selectors will yield the same results, the point here is > performance. > > @north the article is right. Sizzle processes the selector from right > to left, so explicit child relationships and simpler selectors will > make it faster. See for yourself (switch between versions under > "Source" on the left):http://jquery.nodnod.net/cases/474 > > cheers > ricardo > > On Jun 30, 6:04 pm, "Cesar Sanz" <the.email.tr...@gmail.com> wrote: > > > ".nav li a" is very different to ".nav li > a" > > > in the second statement (".nav li > a") only the anchors that are direct > > descendant of "li" elements will be chosen > > in the first statement (".nav li a" ) every anchor will be picked, direct or > > indirect descendant > > > ----- Original Message ----- > > From: "brian" <bally.z...@gmail.com> > > To: <jquery-en@googlegroups.com> > > Sent: Tuesday, June 30, 2009 11:45 AM > > Subject: [jQuery] Re: ul.nav a VS. .nav li > a > > > > I can't speak for Sizzle but, if you'll only ever have one "nav" > > > element on a page, you're better off using an ID than a class. > > > > On Tue, Jun 30, 2009 at 8:03 AM, north<ollo...@web.de> wrote: > > > >> Hi, > > > >> yesterday I read an article about jQuery performance. In one part the > > >> author talks about selectors and uses > > > >> .nav li a > > > >> as an example. He states that before jQuery 1.3., the selector > > > >> ul.nav a > > > >> would have been the best way to get all links in the list. In jQuery > > >> 1.3., due to the inclusion of Sizzle, > > > >> .nav li > a > > > >> "should" be the best way. He doesn't mention any speed tests though, > > >> and only briefly explains that the reason for this is Sizzle's way of > > >> walking through selectors from right to left. > > > >> Can anyone confirm this "theory"? > > > >> Thanks!
