Javascript类库处于关闭状态

Question

I'm attempting to create a JS class library in a closure for a Drupal application (the Drupal thing is not necessarily relevant but style insists on closures). I'm not a coding newbie but JS is not my area of expertise :-)

The first problem I have is that the "extends" doesn't work - I understand that I don't have the right reference for the extends class, but what should it be, because I can't find anything that works?

 ((window) => { window.lib = { LibClassBase: class {} LibClass1: class extends LibClassBase {} } })(window) 

Alternatively: is this just the wrong approach and should I be doing something else?

Answer 1

is this just the wrong approach

Yes.

You can't read a value from an object before it has been constructed.

and should I be doing something else?

Use class declarations and create them within the scope of the closure.

Assign them to the object you are returning afterwards.