The information presented in this chapter is material you will be coming back to again and again and again when you write programs. Loops are a fundamental part of most coding languages. In several of the hours to come, you get a chance to manipulate graphics so you can produce animated effects. You couldn't do this without loops. As you might expect, every one of Bart Simpson's chalkboard punishments has been documented on the World Wide Web. Visit to see the list along with a Java applet that draws sayings on a green chalkboard.