IN THIS CHAPTER
Writing methods that work with existing values
Building methods that modify existing values
Making methods that return new values
In Chapters 3 and 4, I introduce Java methods. I show you how to create a
main method and how to call the
System.out.println method. Between that chapter and this one, I make very little noise about methods. In Chapter 18, I introduce a bunch of new methods for you to call, but that’s only half of the story.
This chapter completes the circle. In this chapter, you create your own Java methods — not the tired old
main method that you’ve been using all along, but rather some new, powerful Java methods.
In Chapter 18, Figure 18-6 introduces an interesting notion — a notion that’s at the core of object-oriented programming. Each Java string has its own
equals method. That is, each string has, built within it, the functionality to compare itself to other strings. That’s an important point. When you do object-oriented programming, you bundle data and functionality into a lump called a class. Just remember Barry’s immortal words from Chapter 17:
A class … describes the way ...