Convert string into jQuery object and select inner element

I wonder if there is a way to convert 开发者_StackOverflow中文版string into jQuery object and select inner elements without injecting the whole string into DOM and manipulate it in there. Thanks.

If possible, please give me example of converting

<div id=a1></div>
<div id=a3></div>

And select a1 from the object variable.

This will create elements from the html and find the a1 element:

var element = $('<div id="a1"></div><div id="a3"></div>').filter('#a1').get(0);

The correct way to do this is:

var a1 = $('<div id="a1"></div><div id="a3"></div>').filter('#a1')[0];

Getting the DOM element out with [0] is equivalent to .get(0).

Update: interesting, I've never come across this corner case before but this:

var a1 = $("#a1", "<div id=a1><//div><div id=a3><//div>")[0];

doesn't work when the element is at the top level, which I consider to be a bug. I've never come across that before so I thought I'd leave it up here as a cautionary tale. Thanks to Crescent Fresh for pointing that out.