title: value type reference type object in javascript
body: <p>Are javascript objects value based or reference based?  For example:</p>
  
  <pre><code>obj1.list =new array();
  // ------ populate list
  obj2.list = obj1.list
  </code></pre>
  
  <p>Does the browser make different copy of the obj1.list for obj2.list, or is obj2.list just a reference to obj1.list?</p>