Summary

This chapter took the basic class structure we presented in Chapter 4 and expanded it by introducing the notion of inheritance. Java classes follow a multilevel single-inheritance pattern in which every class has exactly one direct parent class, with all classes eventually inheriting from java.lang.Object. Java interfaces simulate a limited form of multiple inheritance, since Java classes may implement multiple interfaces.

Inheriting a class gives you access to all of the public and protected methods of the class, but special rules for constructors and overriding methods must be followed or the code will not compile. For example, if the parent class doesn't include a no-argument constructor, an explicit call to a parent constructor must be provided in the child's constructors. Pay close attention on the exam to any class that defines a constructor with arguments and doesn't define a no-argument constructor.

We reviewed overloaded, overridden, and hidden methods...