Java How to Program, Early Objects, 11th Edition

9.3 protected Members

Chapter 8 discussed access modifiers public and private. A class’s public members are accessible wherever the program has a reference to an object of that class or one of its subclasses. A class’s private members are accessible only within the class itself. In this section, we introduce the access modifier protected. Using protected access offers an intermediate level of access between public and private. A superclass’s protected members can be accessed by members of that superclass, by members of its subclasses and by members of other classes in the same package—protected members also have package access.

All public and protected superclass members retain their original access modifier when they become members of the subclass— ...