jQuery select elements only if they aren't nested within like elements

Question

Assuming the following:

<div class="a"> <!-- select -->
  <div class="b">
    <div class="a"> <!-- skip -->
    </div>
  </div>
</div>

<div class="b">
   <div class="a"> <!-- select -->
     <div class="b">
        <div class="a"> <!-- skip -->

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

<div class="a"> <!-- select -->

</div>

How do I only select the outermost $('.a') elements?

Edit: A helpful JSFiddle, in this example, only 'a' should be selected, not 'a!'.

Answer 1

This is where filter methods come in handy:

$('.a').not('.a .a');

This excludes any .a that is nested within another .a so you only get the outermost ones, regardless of whether the outermost ones are themselves nested within other elements.

Answer 2

Try using the jQuery :not selector

$('.a:not(.a .a)')

http://jsfiddle.net/7E7Mk/1/