what is the point of heterogenous arrays?

Question

I know that more-dynamic-than-Java languages, like Python and Ruby, often allow you to place objects of mixed types in arrays, like so:

[\"hello\", 120, [\"w         


        

Answer 1

Applying a multimethod to the array might make some sense. You switch the strategy to a more functional style in which you focus on a discrete piece of logic (i.e. the multimethod) instead of a discrete piece of data (i.e. the array objects).

In your shapes example, this prevents you from having to define and implement the Shape interface. (Yes, it's not a big deal here, but what if shape was one of several superclasses you wanted to extend? In Java, you're SOL at this point.) Instead, you implement a smart draw() multimethod that first examines the argument and then dispatches to the proper drawing functionality or error handling if the object isn't drawable.

Comparisons between functional and object-oriented styles are all over the place; here are a couple relevant questions that should provide a good start: Functional programming vs Object Oriented programming and Explaining functional programming to object-oriented programmers and less technical people.