Thanks Guys,
That has been very helpful.
On Jul 12, 4:52 pm, "Michael Geary" <[EMAIL PROTECTED]> wrote:
> Yeah, as Klaus mentioned, it is a tiny bit faster if you leave out the
> 'img'.
>
> The real optimization you can do is to avoid using the same selector
> repeatedly. In a way, jQuery makes it too easy to write inefficient code:
>
> $('#foo').doSomething();
> // ...later...
> $('#foo').doSomethingElse();
>
> Replace that with:
>
> var $foo = $('#foo');
> $foo.doSomething();
> // ...later...
> $foo.doSomethingElse();
>
> As you can see, I use $variableName as a convention to remind me that the
> variable is a jQuery object.
>
> This will make more of a difference with slower selectors like
> $('.someClass'). Even though jQuery is much faster than it used to be, it's
> still faster if you can avoid repeating the selector query at all.
>
> -Mike
>
> > From: NeilM
>
> > I have just started to use jQuery in my web development and
> > have a question concerning optimising element selection.
>
> > I find that I create a lot of references to id'd elements:
>
> > <img id="myImage" src="todaysimage.gif" width="20" height="20" />
>
> > Then, in my JavaScript, I want to obtain a reference to the element.
> > Now, even though it has an id, I tend to use the full CSS
> > descriptor as, to me anyway, it makes the code more readable:
>
> > $("img#myImage").addClass("border");
>
> > My question is, apart from the overhead of some extra
> > characters in the script (e.g. 'img#'), does this style of
> > specification introduce a performance overhead internally
> > within jQuery? Would/does jQuery optimise the element
> > selection process if it just 'sees' a simple id string
> > starting with a #?
>
> > $("#myImage").addClass("border");
