title: Get the object length in angularjs is undefined
body: <p>How can I get the object length ?</p>
  
  <p>In console my object looks like this: </p>
  
  <pre><code>Object {
   2: true,
   3: true,
   4: true
  }
  </code></pre>
  
  <p><code>.length</code> will give me <strong>undefined</strong>. I just want to get the <code>results = 3</code> for this case.</p>