> Every time I think I understand Javascript, I read something about its prototypes and constructors and how 'new' and 'this' works and I am lost again.
Prototypes, constructors, and context are not that complicated; I encourage you to keep reading and trying things. You may be surprised how quickly you end up "getting" it.
> The thing I like about classes is I vaguely understand what is going on and why, coming from Java and similar.
No. The class keyword in JS is syntactic sugar around the same prototype stuff that already existed. It does not work like it does in Java, and you will not understand what it's doing unless you understand how the class keyword translates directly into manipulating the prototype chain.
Which, as above, is easy! But if there's one actual problem with the class keyword it's that it makes people who know Java think they understand JS inheritance.
The class keyword DOES NOT CHANGE YOUR CODE. If you didn't understand what was going on before you used the class keyword, you don't understand it after adding it in. (Conversely, if you actually do understand how the class keyword works, then rejoice, you now understand how prototypes work...)
>Which, as above, is easy! But if there's one actual problem with the class keyword it's that it makes people who know Java think they understand JS inheritance.
Which is totally fine, as for all intends and purposes the behavior is the same. You create new instances, and you call methods on them.
The "movable" context (this) will be a little surprising, but for everything else one can write JS for decades with ES6 classes and "OOP", without having to know how the prototypes, objects and functions they de-sugar to work.
> Which is totally fine, as for all intends and purposes the behavior is the same.
Nope :) They're apparently the same, which is not the same as "the same".
> The "movable" context (this) will be a little surprising, but for everything else one can write JS for decades with ES6 classes and "OOP", without having to know how the prototypes, objects and functions they de-sugar to work.
That's just the thing though - there isn't a "movable context", there is only binding. Binding usually happens implicitly, and most of the time things are implicitly bound to what you expect them to be if you're not aware it's happening.
... then comes the moment that you're in an instance's method, and `this` is pointing to an event instead of the object. Oh, boy.
In my experience that moment comes much more often than once every few decades.
Prototypes, constructors, and context are not that complicated; I encourage you to keep reading and trying things. You may be surprised how quickly you end up "getting" it.
> The thing I like about classes is I vaguely understand what is going on and why, coming from Java and similar.
No. The class keyword in JS is syntactic sugar around the same prototype stuff that already existed. It does not work like it does in Java, and you will not understand what it's doing unless you understand how the class keyword translates directly into manipulating the prototype chain.
Which, as above, is easy! But if there's one actual problem with the class keyword it's that it makes people who know Java think they understand JS inheritance.
The class keyword DOES NOT CHANGE YOUR CODE. If you didn't understand what was going on before you used the class keyword, you don't understand it after adding it in. (Conversely, if you actually do understand how the class keyword works, then rejoice, you now understand how prototypes work...)