Java™ How to Program, Seventh Edition

Summary

Section 10.1 Introduction

• Polymorphism enables us to write programs that process objects that share the same superclass in a class hierarchy as if they are all objects of the superclass; this can simplify programming.

• With polymorphism, we can design and implement systems that are easily extensible—new classes can be added with little or no modification to the general portions of the program, as long as the new classes are part of the inheritance hierarchy that the program processes generically. The only parts of a program that must be altered to accommodate new classes are those that require direct knowledge of the new classes that the programmer adds to the hierarchy.

Section 10.3 Demonstrating Polymorphic Behavior

• When the compiler ...