title: Detect if collection contains data
body: <p>It may be a simple question, but I can't find the answer. How can I know if my Collection has no data ?</p>
  
  <p>I do <code>$datas = Mage::getModel('zzz/zzz')-&gt;getCollection()</code> if I do a <code>$datas-&gt;getData()</code> it returns an empty array, but how do I know if my collection has no data without doing foreach or getData ?</p>