Programming in Objective-C, Fifth Edition

5. Program Looping

In Objective-C, you can repeatedly execute a sequence of code in several ways. These looping capabilities are the subject of this chapter, and they consist of the following:

• The for statement

• The while statement

• The do statement

We start with a simple example: counting numbers.

If you were to arrange 15 marbles into the shape of a triangle, you would end up with an arrangement that might look something like Figure 5.1.

Figure 5.1. Triangle arrangement example

The first row of the triangle contains one marble, the second row contains two marbles, and so on. In general, the number of marbles required to form a triangle ...