C++ How to Program, 10/e

... increment the appropriate letter-grade counter based on the numeric grade entered.

Processing the Grades

The switch statement (lines 29–50) determines which counter to increment. We assume that the user enters a valid grade in the range 0–100. A grade in the range 90–100 represents A, 80–89 represents B, 70–79 represents C, 60–69 represents D and 0–59 represents F. The switch statement consists of a block that contains a sequence of case labels and an optional default case. These are used in this example to determine which counter to increment based on the grade.

When the flow of control reaches the switch, the program evaluates the expression in the parentheses (grade / 10) following keyword switch. This is the switch’s controlling expression. The ...