[ffsm8]

As a full stack developer who's current job is mostly Java on the backend - at least for the last 8 yrs: I'm not aware of anything you would lose by switching to interfaces with default implementations over inheritance... And that's the usual argument: use composition over inheritance.

[yorwba]

But would switching to interfaces with default implementations fix any of the complaints that people have about inheritance? In my mind, they're pretty much equivalent, so it seems to me that anything you can do with inheritance that people complain about, you could also do with interfaces and complain about it in the same way.

[ffsm8]

The biggest difference are

1. A class can be composed out of multiple interfaces, making them more like mixins/traits etc vs inheritance, which is always a singular class

2. The implementation is flat and you do not have a tree of inheritance - which was what this discussion was about. This obviously comes with the caveat that you don't combine them, which would effectively make it inheritance again.