how come in php superclasses can access protected methods of their subclasses?

Question

I just noticed this behavior today - weird, I'm pretty sure in java a you can only access protected methods upstream on the inheritance chain since going the other way violates encapsulation.

Was there a reason for this behavior in the language?

Answer 1

This is allowable in Java as well. This is probably allowed in Java however, since protected is also considered to be package level scope and not just relegated to access within the inheritance chain.

Answer 2

This link may be helpful for your answer:

http://www.velocityreviews.com/forums/t129550-why-is-a-superclass-allowed-to-access-protected-methods-of-a-subclass.html

I hope it helps you.

Answer 3

I've found it useful when one method defined in the parent only needs a small part of its functionality to change based on the extension class type. You can call an abstract method from within the parent, and it's functionality changes as needed with the definition of that method in the child classes.

I would also add that sibling classes can also access each other's protected properties and methods, as long as they are declared in the parent class (this can be abstract or not).

Answer 4

protected != private