><a class="toggle-link" href="#comment-count-e2942a04780e223b215eb8b663cf5353">var count</a> <span class="required">Required</span><div class="comment collapse in" id="comment-count-e2942a04780e223b215eb8b663cf5353"><p>The number of elements in the collection.</p>
<p>To check whether a collection is empty, use its <code>isEmpty</code> property
instead of comparing <code>count</code> to zero. Unless the collection guarantees
random-access performance, calculating <code>count</code> can be an O(<em>n</em>)
op