Honestly I can’t remember half the dom manipulation stuff and at one point I did know it quite well. It’s just been 6 years since I worked on an app that wasn’t react.
It’s useless knowledge for most people now. Like knowing assembly.
I wouldn't really consider anything involving the DOM to be a JS fundamental. That's a browser fundamental, and even then, it's like, what do you want? I can use `document.write('hello world')` and replace the entire body. Or append it as a text node with `document.body.append`. Or create an element and add it. This is a pretty silly question and something people should just spend 2 seconds looking up on the rare occasion they need to do it.
I currently work with devs who've done things like create a Map and then assign properties directly instead of using .set and .get.. I'd say that shows a pretty significant lack of fundamentals
I believe Map was released in 2015 as part of ES6 so while not new, it still feels new in some code bases. Some people also confuse it with Array.prototype.map a lot.
People just assume every data structure operates like an array since it is the most commonly used without realizing the underlying object nature of the language. Like the idea of getters and setters coming from OOP paradigm is lost to fresh devs over the last 5 years using the FP paradigm as their primary means of coding in React.
So yeah some of the fundamental are missing but also most of the time this knowledge probably isn't utilized by React FP only devs in their day to day.
