title: Mongoose count number of returned array?
body: <pre><code>User.find({job:"developer",sick:1},callback);
  </code></pre>
  
  <p>Above query gave me numbers of arrays object, but I just need the length of it. I tried <code>User.count({job:"developer",sick:1},callback);</code> it doesn't work.</p>
  
  <p>I know I can use native <strong>.length</strong> native function but I want to use <strong>count()</strong> to optimize my query. </p>