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jQuery – Fast selectors using Context
Posted by: qrpike
Tags:
javascript, JQuery, optimization, selectors
Posted date:
November 21, 2011 |
No comment
One of the biggest performance areas of javascript and jQuery is the selectors.
Selectors are basically what we tell jQuery to select in the DOM that we want to manipulate. For example $(‘#header’) would select the entire header div, with this we can do what we want.
Problem is, when we have pages with thousands of dom elements, cycling through them all takes a bit of time. So to speed things up, we can tell jQuery exactly where to look. This is called context. Context tells jQuery to only look in this spot.
With Context: (Correct Way)
$('#logo',$('#header')[0]).css();
Without Context: (Slow Way)
$('#logo').css()
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