Question

I just want to know if instead of

$(".element1").css('background','#000');
$(".element2").css('background','#000');

It is possible to concatinate multiple elements to have them affected by one command or if there is a more efficient way like so:

$(".element1",".element2").css('background','#000');

Answer 1

CSS selectors have always supported unions:

$(".element1, .element2").css('background','#000');

You can also add to the jQuery element set yourself:

$(".element1").add(".element2").css('background','#000');

All you needed was a cursory glance at the documentation.