Sams Teach Yourself C++ in 21 Days

On lines 12–15, the numbers are entered. Line 20 sets up a whileloop, which will con-

tinue only as long as two conditions are met:

1. Small is not bigger than large.


2. Small doesn’t overrun the size of a small integer (MAXSMALL).
   On line 22, the value in smallis calculated modulo 5,000. This does not change the
   value in small; however, it only returns the value 0 when smallis an exact multiple of
   5,000. Each time it is, a dot (.) is printed to the screen to show progress. On line 25,
   smallis incremented, and on line 26,largeis decremented by 2.
   When either of the two conditions in the whileloop fails, the loop ends and execution of
   the program continues after the whileloop’s closing brace on line 27.

180 Day 7

The modulus operator (%) and compound conditions were covered on Day 3,

“Working with Variables and Constants.”

NOTE

Introducing continueand break....................................................................

At times, you’ll want to return to the top of a whileloop before the entire set of state-

ments in thewhileloop is executed. The continuestatement jumps back to the top of

the loop.

At other times, you might want to exit the loop before the exit conditions are met. The

breakstatement immediately exits the whileloop, and program execution resumes after

the closing brace.

Listing 7.4 demonstrates the use of these statements. This time, the game has become

more complicated. The user is invited to enter a small number and a large number, a skip

number, and a target number. The small number will be incremented by one, and the

large number will be decremented by 2. The decrement will be skipped each time the

small number is a multiple of the skip. The game ends if smallbecomes larger than

large. If the large number reaches the target exactly, a statement is printed and the game

stops.

The user’s goal is to put in a target number for the large number that will stop the game.