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jquery
Torben
Torben

Reputation: 5494

JQuery: Why using .find()

why are some developers using JQuery's .find-function like this:

$(document).find('.progress').show();

If you know the name of the class, you can just use:

$('.progress').show();

Even if i have ul-lists and want to select all li-children i can do this just with

$('li')...

Appreciate some clarity...Thanks!

Upvotes: 0

Views: 195

Answers (2)

Gregg B
Gregg B

Reputation: 13727

There is a performance hit to using a class directly since it doesn't map to native JS like getElementbyID or getElementbyTagName

find() will often be much more efficient (for pages with a large number of elements).

Edit::

Found the article I remembered this from. #5 here http://dumitruglavan.com/jquery-performance-tips-cheat-sheet/

  1. Use find() rather than context Indeed, the .find() function seems to be faster. But this counts more when you have a lot of traversing a page with lots of DOM elements:
var divs = $('.testdiv', '#pageBody'); // 2353 on Firebug 3.6

var divs = $('#pageBody').find('.testdiv'); // 2324 on Firebug 3.6 - The best time

var divs = $('#pageBody .testdiv'); // 2469 on Firebug 3.6

Upvotes: 1

SLaks
SLaks

Reputation: 887767

The point of .find() is to find elements within a parent element.

There is no point in $(document).find(...).

Upvotes: 2

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