<!DOCTYPE html>
<html>
<title>W3.JS</title>
<script src="/Uploads/Public/article/webdistut/javascript/w3.js"></script>
<body>

<p>Click the button to hide the first p element inside div.</p>

<button onclick="w3.hide('div p:first-child')">Hide</button>

<div>
  <p>First paragraph.</p>
  <p>Second paragraph.</p>
</div>

</body>
</html>

Click the button to hide the first p element inside div.

First paragraph.

Second paragraph.