You can use the classList
property
to check what classes have been assigned to a DOM element.
Assuming the following DOM element:
<div id="auth-modal" class="modal hidden">...</div>
Once you get a handle on that element, using your preferred method (e.g.
Document.getElementById
),
you can start inspecting the class list:
> element.classList.contains("modal")
true
> element.classList.contains("hidden")
true
> element.classList.contains("taco")
false
> element.classList.toString()
"modal hidden"