JavaScript’s document.querySelector() same as jQuery $() method?

Cross-browser and legacy support.

You can also use getElementsByClassName() if you don’t want to use Jquery. There is a response to a post on devshed by user: KorRedDevil that may be of interest to you.

I took your function from your post and made it return an array. After you have that array of elements, all you have to do is loop over them. You can try it out here.

Javascript:

var retrieve = function(className) {
    return document.getElementsByClassName(className);
};

var elements = retrieve('foo');
for (var i = 0; i < elements.length; i++)
    elements[i].style.background = '#dfd';

Markup:

<p class="foo">foo</p>
<p class="bar">bar</p>
<p class="foo">foo</p>
<p class="foo">foo</p>
<p class="bar">bar</p>
<p class="bar">bar</p>