title: Split string every 3 characters from back using JavaScript
body: <p>How do we split a string every 3 characters from the back using JavaScript?</p>
  
  <p>Say, I have this:</p>
  
  <pre><code>str = 9139328238
  </code></pre>
  
  <p>after the desired function, it would become:</p>
  
  <pre><code>parts = ['9','139','328','238']
  </code></pre>
  
  <p>How do we do this elegantly?</p>