Chapter 6 - Decision Making

Summary

OBJECTIVES

In this chapter you will study:

• Conditions;

• Logical operators;

• if … else structure;

• Case structure;

• Java switch; and

• Java break.

In this chapter you will learn how to implement the selection and case structure using Java. You will see how to write if and switch statements. Java and COBOL if statements are very similar and therefore straightforward. However, switch is a distant cousin of the COBOL EVALUATE verb and has some similarities, but it also has many important differences, which will be discussed and illustrated in this chapter.

We will first examine the Java logical operators, conditions, and the if statement. This discussion includes the emulation of COBOL condition names using Java. Next we present the switch statement and explain its use. The chapter concludes with the development of a new method, computeServiceCharge(), for Checking Account. This method is first written using nested if statements, then written again using switch.

The chapter assumes you understand the following:

COBOL

Condition names

Logical operators

IF—ELSE—END—IF

EVALUATE

CONTINUE

Java

OO concepts (Chapter 2)

Java program structure (Chapter 3)

Defining data (Chapter 4)

Computation (Chapter 5)

SERVICE CHARGES AT COMMUNITY NATIONAL BANK

The Community National Bank system computes a service charge for each checking account each month.