Chapter 4 began our introduction to the types of building blocks that are available for problem solving. We used those building blocks to employ proven program construction techniques. In this chapter, we continue our presentation of the theory and principles of structured programming by introducing C++'s remaining control statements. The control statements we study here and in Chapter 4 will help us in building and manipulating objects. We continue our early emphasis on object-oriented programming that began with a discussion of basic concepts in Chapter 1 and extensive object-oriented code examples and exercises in Chapters 34.
In this chapter, we demonstrate the for, do...while and switch statements. Through a series of short examples using while and for, we explore the essentials of counter-controlled repetition. We devote a portion of the chapter to expanding the GradeBook class presented in Chapters 34. In particular, we create a version of class GradeBook that uses a switch statement to count the number of A, B, C, D and F grades in a set of letter grades entered by the user. We introduce the break and continue program control statements. We discuss the logical operators, which enable programmers to use more powerful conditional expressions in control statements. We also examine the common error of confusing the equality (==) and assignment (=) operators, and how to avoid it. Finally, we summarize C++'s control statements and the proven problem-solving techniques presented in this chapter and Chapter 4.