6

CHAPTER

we introduced some general techniques for solving simple
problems. In the real world, many programming problems are collections
of multiple problems that must be solved in a coordinated manner. We
now know enough Java syntax to solve many such problems, but we need
to learn how to organize our problem solving to achieve success in the face
of greater complexity.
In this chapter, we reexamine the programming process and intro-
duce a software design strategy that helps us tame the seemingly vast ar-
ray of details that accompany a larger problem. In particular, we formalize
the concepts of object-oriented design and present the CRC card design
technique.
We revisit the class construct, the implementation structure that we
use to code our object-oriented design. Once we have a design in the
form of CRC cards, we see how to convert it into a class. As part of this
process, we look at the user interface, the implementation of the re-
sponsibility algorithms, and the testing of the class. Then we explore
how to use Java packages to organize groups of classes.
Finally, we take the opportunity to emphasize that professional re-
sponsibility comes with the skills that this book teaches.

In Chapter 1,

1959

Xerox debuts the

first commercial

copy machine

1959

General Electric

develops the GE

ERMA, the first

machine that can

process checks

encoded with

magnetic ink

1960

Digital Equipment

Corporation debuts

the PDP-1, which

has a monitor and

keyboard input

1961

The first robot

patent is obtained

by Georg Devol

whose “Unimates”

are the first modern

industrial robots

1961

Computer

capabilities launch

forward with the

IBM 7030, which

runs 30 times faster

than the 704

1962

The first computer

science departments

are established at

Stanford University

and Purdue

University