Why does setting positions in a subclass of Array not change its length? Should I not subclass array?

Question

In the CoffeeScript program below, I create a subclass of Array which sets two positions in its constructor:

class SetPositionsArray extends Arr         


        

Answer 1

I realize I'm rather late in the game here, but you shouldn't need to do what you're doing. Here's an example I've been tinkering with and I see no reason why it shouldn't work for you.

class ArrayWrapper
  constructor: (name, args...)
    @name = name
    @push.apply(@, args)

Once this is in place I can do this:

>>> relation = new Relation('foo',1,2,3,4,5)
Object[1, 2, 3, 4, 5]
>>> relation.length
5