DOM: List/Add/Remove Class Attribute

Here's methods to list/add/remove a HTML/XML element's class attribute.

• elem.classList → Returns elem's class attribute's space separated values as a array-like object.
• elem.classList.add(class_name) → Adds a class value to a element class attribute. If already exists, it will not add the class again.
• elem.classList.remove(class_name) → Removes a class value to a element class attribute. No error if doesn't exist.
• elem.classList.toggle(class_name) → Toggle a class value.
• elem.classList.toggle(class_name,force) → force is true or false. If true, always add the class. Else, toggle.
• elem.classList.contains(class_name) → returns true if elem contains the class value, else false.

Example:

<div id="x48389" class="aaa bbb ccc"></div>

const xx = document .getElementById("x48389");

xx.classList;

xx.classList.add("hh");

xx.classList.remove("bbb");

xx.classList.contains("aaa");

xx.classList.toggle("aaa");