Java 6 Illuminated: An Active Learning Approach, 2nd Edition

284 CHAPTER 6 Flow of Control,Part 2: Looping

of the loop will be required. We rely on a signal, or event, to tell us that we

have processed all the data. For example, when the cashier begins checking

out an order, she doesn’t (necessarily) know how many items are in the gro-

cery cart; she only knows to stop when she sees the divider bar on the con-

veyor belt. We call this an event-controlled loop because we continue

processing data until an event occurs, which signals the end of the data.

When we’re prompting the user to enter data from the console, and we

don’t know at the beginning of the loop how much data the user has to be

processed, we can define ...