Introduction

Before writing a program to solve a problem, it is essential to have a thorough understanding of the problem and a carefully planned approach to solving it. When writing a program, it is also essential to understand the types of building blocks that are available and to employ proven program-construction techniques. In this chapter and in Chapter 5, Control Statements: Part 2, we discuss these issues in our presentation of the theory and principles of structured programming. The concepts presented here are crucial in building classes and manipulating objects.

In this chapter, we introduce Java's if, if...else and while statements, three of the building blocks that allow programmers to specify the logic required for methods to perform their tasks. We devote a portion of this chapter (and Chapters 5 and 7) to further developing the GradeBook class introduced in Chapter 3. In particular, we add a method to the GradeBook class that uses control statements to calculate the average of a set of student grades. Another example demonstrates additional ways to combine control statements to solve a similar problem. We introduce Java's compound assignment operators and explore Java's increment and decrement operators. These additional operators abbreviate and simplify many program statements. Finally, we present an overview of the primitive data types available to programmers.