> But why would you want to be able to pass an apple to a function expecting a banana?
I would never. I know that I'm holding a banana, I want to pass it to a method that receives a banana. But what I can't do is put my banana through a rotateFruit function first, because then Java will forget that it's a banana and start treating it as a fruit.
Inheritance is just a tool, that you use if it fits you software architecture. You use other tools, like generics, interface, where it makes senses to ise them. I think people wants the one true way to not have to design their software. And when they use inheritance in a ways that does not fit, they blame inheritance.
If you pass your object to another function, you only get static dispatch. What you want instead in this case, is a simple instance method. Then yourApple.rotateFruit() would do what you want, and rutateFruit could be an interface method declared in Apple, the superclass/interface.
I would never. I know that I'm holding a banana, I want to pass it to a method that receives a banana. But what I can't do is put my banana through a rotateFruit function first, because then Java will forget that it's a banana and start treating it as a fruit.