Question

A moment ago I asked this question:
javascript sort array to align with order array based on what turned out to be a false premise. (I’ve been up for too long, give me a break please).

What I really need to do is sort DOM elements. Performance is key in my application as it will be running in very CPU-poor situations. So what I have is something like this:

<div id="moduleWrap">
    <div class="module">Jack</div>    <!-- 0 -->
    <div class="module">Jill</div>    <!-- 1 -->
    <div class="module">Nancy</div>   <!-- 2 -->
    <div class="module">Tom</div>     <!-- 3 -->
    <div class="module">Cartman</div> <!-- 4 -->
</div>

And in JavaScript:

$modules = $('#moduleWrap .module');
order    = [3,1,4,0,2];

What I need is this:

<div id="moduleWrap">
    <div class="module">Tom</div>     <!-- 3 -->
    <div class="module">Jill</div>    <!-- 1 -->
    <div class="module">Cartman</div> <!-- 4 -->
    <div class="module">Jack</div>    <!-- 0 -->
    <div class="module">Nancy</div>   <!-- 2 -->
</div>

I thought (wrongly) that I could sort the jQuery object and simply append the result. This is not so.

Answer 1

I would just iterate over the order array and rearrange the DOM elements accordingly:

var elements = [];
$.each(order, function(i, position) {
    elements.push($modules.get(position));
});

$('#moduleWrap').append(elements);

DEMO

To increase performance, you can take away more and more jQuery. For example:

var wrapper = document.getElementById('moduleWrap');
for(var i = 0, l = order.length; i < l; i++) {
    wrapper.appendChild($modules.get(order[i]));
}

DEMO

jQuery is great because it makes things easy, but if you need high performance, you should rather go without it.