 <p>In JSON (by standard) you have <a href="http://www.json.org/" rel="nofollow">Arrays, Objects, values and strings</a>, arrays are not Objects like in JavaScript. JSON is only a data-interchange format, you don't have a base prototype like in JavaScript where almost everything is an object and have properties.</p> <p>So, if you want to have a property <code>z3</code> of <code>z2</code> you have to make <code>z2</code> an object.</p>