Beginning Programming with C++ For Dummies, 2nd Edition

Chapter 7

Switching Paths

In This Chapter

Using the switch keyword to choose among multiple paths

Taking a default path

Falling through from one case to another

Often programs have to decide between two options: Either m is greater than n or it’s not; either the lug nut is present or it’s not. Sometimes, however, a program has to decide on one option out of a large number of possible legal inputs. This situation could be handled by a series of if statements, each of which tests for one of the legal inputs. However, C++ provides a more convenient control mechanism for selecting among multiple options: the switch statement. This chapter gives you a closer look at what the switch statement is, what it does, and how to use it.

Controlling Flow with the switch Statement

The switch statement has the following format:

  switch(expression){  case const1:    // go here if expression == const1    break;  case const2:    // go here if expression == const2    break;  case const3:         // repeat as often as you like    // go here if expression == const3    break;  default:    // go here if none of the other cases match}

Upon encountering the switch statement, C++ evaluates expression. It ...