How to add new class in div via javascript?

Question

Hello Everyone i am using wordpress slider but i want to add new class in slider <li> via javascript.

<div class="wp-slider">
 <ul>
 <li></li>
 </ul>
</div>

Answer 1

In Javascript :

document.querySelector('.wp-slider ul li').classList.add('MyClass')

(or in JQuery :)

$('.wp-slider ul li').addClass("MyClass")