title: Does "for...of" loop iteration follow the array order in JavaScript?
body: <p>Iterating over an array using <code>for...in</code> doesn't guarantee order, however ES6 introduces a new construct <code>for...of</code>. </p>
  
  <p>My limited testing of implementations of <code>for...of</code> indicates that it does iterate in order on array, but is this property guaranteed?</p>