Java All-in-One For Dummies, 5th Edition

Chapter 4

Using Subclasses and Inheritance

IN THIS CHAPTER

Explaining inheritance

Creating subclasses

Using protected access

Creating final classes

Demystifying polymorphism

Creating custom exception classes

As you find out in Book 3, Chapter 1, a Java class can be based on another class. Then the class becomes like a child to the parent class: It inherits all the characteristics of the parent class, good and bad. All the fields and methods of the parent class are passed on to the child class. The child class can use these fields or methods as they are, or it can override them to provide its own versions. In addition, the child class can add fields or methods of its own.

In this chapter, you discover how this magic works, along with the basics of creating and using Java classes that inherit other classes. You also find out a few fancy tricks that help you get the most out of inheritance. ...