title: Add element in post array using php
body: <p>I have a $_POST array and I would like to add a key at the very end.</p>
  
  <p>So what I am doing is,</p>
  
  <pre><code>array_push($_POST['ques_15'] , '');
  </code></pre>
  
  <p>it works but I am getting a warning</p>
  
  <pre><code>Warning: array_push() expects parameter 1 to be array, null given 
  </code></pre>
  
  <p>How can I remove this warning without turning off display errors.</p>