Is there a significant difference if I construct a jQuery object around an element once or many times? For instance:

```
var jEl = $(el);
$.each(myArray, function() {
    jEl.addClass(this);
}

```

versus:

```
$.each(myArray, function() {
    $(el).addClass(this);
}

```

I know there are other ways to write this that might sidestep the issue, but my question is about whether I should work to do $(el) just once, or if it truly is irrelevant. The example is contrived.

Bonus points for explaining just what $(el) does behind the scenes.

I know that theoretically more work is being done, what I don't know is whether it matters... if jQuery caches it or the browsers are all really good at the second request or whatever, than its not worth it.

FYI: The relevant jQuery API link is here (which I provide because $() isn't the easiest thing to Google for): <http://api.jquery.com/jQuery/#using-dom-elements>

Also worth including this useful link: <http://www.artzstudio.com/2009/04/jquery-performance-rules/>, where several of his points center around saving, chaining, and selecting well.