Use jQuery to check if all div's are hidden

Question

How would I check if all the div's with class test are hidden. And if they are all hidden set wrap1 to hidden. Thanks.

<div id='wrap1'>
<div class="header">Header 1</div>
<div class='test'><a href="#">Test 1</a></div>
<div class='test'><a href="#">Test 2</a></div>
<div class='test'><a href="#">Test 3</a></div>
</div>

UPDATE: Thanks everyone for the really quick answers, I got it working. They were all very helpful.

Answer 1

You can do the check as by using selector as suggested above and to it like this:

 if ( $("div.test:visible").length === 0)
      $("#wrap1").hide( );