title: Copying a 3D array
body: <p>I have got a 3D array and I want to make another copy of it into another array.</p>
  
  <p>Assigning directly would return a string to the new array not a 3D array. </p>
  
  <pre><code>foo = [] //3D array; 
  boo = foo //boo becomes a string
  </code></pre>
  
  <p>Any idea of how to do this?</p>
  
  <p>Edit: 
  this is the code</p>
  
  <p><strong>Background.js</strong></p>
  
  <pre><code>function onRequest(request, sender, sendResponse) {
  localStorage = request.mes; // mes is an array
  }; 
  chrome.extension.onMessage.addListener(onRequest);
  </code></pre>