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    <p>One big thing regarding optimization in jQuery is knowing that the jQuery function <code>jQuery()</code> often aliased as <code>$()</code> is indeed a function.</p> <p>That means that using <code>$('#some_id')</code> is actually calling a function which <strong>looks for</strong> the HTML element with the id #some_id. This is costly performance wise because <strong>looking for</strong> something in the DOM means traversing a tree and checking/ comparing the properties of the nodes.</p> <p>You should fetch an HTML element from the DOM (with jQuery) and save the reference into a variable. And later on in the script you'll reference that HTML element using the same variable so as not to traverse the DOM again <strong>looking for</strong> the same element.</p> <p>By using jQuery's <code>method chaining</code> approach (as suggested by @meloncholy) you would obtain the same benefits as defining a variable plus a more compact syntax. This is useful for manipulating an object you don't need a reference to later on, so you just stack-up all the manipulations you need done to it.</p> <p>An example would be:</p> <pre><code>var some_object = $('#some_id'); some_object.hide(); if (some_object.hasClass('some_class')) { ... </code></pre> <p>I can't say that there will be a <strong>noticeable</strong> performance improvement to a script this size. If you had a few hundred lines of jQuery code all abusing the <code>jQuery()</code> function and a few hundred HTML elements in the tree and then you refactored the jQuery code as I indicated then you would have a speedup.</p>
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    1. POHow do i condense this jQuery down so it's more efficient?
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    1. USMihai Stancu
    1. USMihai Stancu
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    1. COJust adding to this: as a lot of jQuery functions return the object you're manipulating, you can use chaining to do several things to the same element in succession. This saves time for the browser as @Mihai Stancu said, and also makes the code more compact, e.g. `$("#button-active").hide().delay(30).fadeIn(1000);`
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