title: looping through arrays of arrays
body: <p>I have an arrays of arrays (some thing like graph), How to iterate all arrays?</p>
  
  <pre><code>var parentArray = [
   [[1,2,3],[4,5,6],[7,8,9]],
   [[10,11,12],[13,14,15],[16,17,18]],
   [[19,20,21],[22,23,24],[26,27,28]]
  ];
  </code></pre>
  
  <p>Its just an example array, actual can contains any number of array and then arrays. How to print all those numbers? Its similar to html objects DOM</p>