D'OH!! I'd not thought of that, but as you point out, the selector is
a string, so it should have occurred to me at some point. Thanks to
yourself and Josh for the replies. As it happens, this is a FAQ for a
number of programming languages I've used, and I usually end up
hunting for an eval() or similar function - this is a lot simpler than
many.
Cheers
Fred
On Oct 27, 9:39 pm, "Josh Nathanson" <[EMAIL PROTECTED]> wrote:
> You want this:
>
> $("#" + fieldset_id);
>
> Don't feel bad, that trips up a lot of people at first (myself included).
>
> Basically the selector is just a string, so you can use the usual JS string
> methods to get what you need.
>
> -- Josh
>
> ----- Original Message -----
> From: "fredriley" <[EMAIL PROTECTED]>
> To: "jQuery (English)" <jquery-en@googlegroups.com>
> Sent: Monday, October 27, 2008 1:13 PM
> Subject: [jQuery] Selecting an element whose ID is in a variable
>
> > This has got to be a FAQ, but I can't see it in the FAQ so here goes,
> > and apologies if it's a stupid question but I'm a relative newbie to
> > jQuery:
>
> > How can I select an element whose id is stored in a constructed string
> > variable?
>
> > What I mean is something like the following. In a document I've got
> > <span> elements with IDs "1", "2", "3", etc, and these correspond to
> > fieldset elements with IDs "part1", "part2", "part3", etc. The user
> > clicks on a <span>, the code gets its ID, constructs the ID of the
> > corresponding <fieldset>, then does something with that (hides it). So
> > something like:
>
> > $("span").click(function()
> > {
> > // get the handle of the clicked element
> > var mySpan = $(this);
> > // get its id
> > var span_id = mySpan.attr("id");
> > // construct the fieldset id
> > var fieldset_id = "part" + span_id;
> > // select the fieldset then hide it - now I'm stuck
> > });
>
> > I've tried the selectors:
>
> > alert($(fieldset_id).attr("id")); // gives 'undefined'
> > alert($(#fieldset_id).attr("id")); // syntax error: illegal character,
> > not surprisingly
> > alert($("#fieldset_id").attr("id")); // gives 'undefined'
>
> > An alternative would be to get the handle of the fieldset element,
> > which could be achieved with the Javascript:
>
> > var id2 = document.getElementById(fieldset_id);
> > alert(id2.id); // gives the id of the fieldset
>
> > but I don't know how to do this in jQuery. I'd prefer to go the whole
> > jQuery hog and not mix it with raw JS, and I could do with
> > understanding how to do this simple operation anyway to improve my
> > jQuery understanding, so tips would be welcome. TIA.
>
> > What I'm trying to do is generalise the specific code in the test at
> >http://www.nottingham.ac.uk/~ntzfr/test/ajax/jquery/show_hide.htmlto
> > handle a form with any number of toggle-able sections.
>
> > Cheers
>
> > Fred
