How does jQuery allow you to use [] on a jQuery object?

Question

Say I had the following markup:

<div></div>
<div></div>
<div></div>

And I use the following to retrieve them:

var divs = $('div');

How is it possible that I am able to retrieve the respective DOM element by using the [] syntax and also be able to call methods on the jQuery object such as .first()?

var div_one = divs[0];

I'm asking this question because it looks to me that divs is a jQuery object, not a true JavaScript Array object.

How does this work?

Answer 1

The numeric indices are just properties of the returned object. It's similar to doing this:

var obj = {};
obj[0] = 'foo';
alert(obj[0]);

Arrays and pseudo-array objects are almost identical - the only difference is that the length property of a true array is automatically managed by the JavaScript engine.