title: Get array of object's keys
body: <p>I would like to get the keys of a JavaScript object as an array, either in jQuery or pure JavaScript.</p>
  
  <p>Is there a less verbose way than this?</p>
  
  <pre><code>var foo = { 'alpha' : 'puffin', 'beta' : 'beagle' };
  var keys = [];
  for (var key in foo) {
      keys.push(key);
  }
  </code></pre>