title: unable to get jsonEncode in magento2
body: <p>Magento has its own json encode and decode functions:</p>
  
  <pre><code>Mage::helper('core')-&gt;jsonEncode($array);  
  </code></pre>
  
  <p>Above code in depreciated in Magento 2. So how to use jsonEncode, what I have to extend to use json Encode?</p>