https://developer.mozilla.org/en-US/docs/Web/API/Element/classList
Element: classList property - Web APIs | MDN
The read-only classList property of the Element interface contains a live DOMTokenList collection representing the class attribute of the element. This can...
web apiselementclasslistpropertymdn
https://johnkavanagh.co.uk/articles/classlist-in-javascript-add-remove-toggle-contains/
classList in JS: Add(), Remove(), Toggle(), Contains() | John Kavanagh
May 14, 2026 - Use classList in JavaScript for add(), remove(), toggle(), and contains(), with cleaner DOM state updates, validation examples, and className cautions.
classlistjsaddremovetoggle
https://blog.learnjavascript.online/posts/javascript-has-class/
JavaScript hasclass using classList - Learn JavaScript Blog
JavaScript has class: using classList to check if an element has a class or not in JavaScript
javascriptusingclasslistlearnblog
https://www.syncfusion.com/feedback/5613/stackblitz-cannot-read-property-classlist-of-undefined-and-cannot-read-property
(stackblitz) Cannot read property 'classList' of undefined AND Cannot read property 'getFullYear'...
Bug reported in Angular - Calendar - (stackblitz) Cannot read property 'classList' of undefined AND Cannot read property 'getFullYear' of null.
stackblitzcannotreadpropertyclasslist
https://caniuse.com/?search=ciu/classlist
"ciu/classlist" | Can I use... Support tables for HTML5, CSS3, etc
can i usesupport tablesciuclasslist