title: Javascript data structure for fast lookup and ordered looping?
body: <p>is there a data structure or a pattern in Javascript that can be used for both fast lookup (by key, as with associative arrays) and for ordered looping?</p>
  
  <p>Right, now I am using object literals to store my data but I just disovered that Chrome does not maintain the order when looping over the property names.</p>
  
  <p>Is there a common way to solve this in Javascript?</p>
  
  <p>Thanks for any hints.</p>