title: Is object empty?
body: <p>What is the fastest way to check if an object is empty or not?</p>
  
  <p>Is there a faster and better way than this:</p>
  
  <pre><code>function count_obj(obj){
      var i = 0;
      for(var key in obj){
          ++i;
      }
  
      return i;
  }
  </code></pre>