<html lang="en"><head><title>jQuery addClass() Method</title><script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script><script>$(document).ready(function(){ $("#btn-add").click(function(){ $("#para-add").addClass("myaddclass"); });});</script><style>.myaddclass{ background:#ccc; padding:10px;}</style></head><body><h2>jQuery addClass() Method</h2><p>When you click the below button, it adds the class <code>'myaddclass'</code> to the below p element.</p><button id="btn-add">Click to Add Class</button><p id="para-add">This is the jQuery Tutorial of add CSS class.</p></body></html>