Get array of object's keys
<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>
