Our Hello, World application was a good introduction to iOS development using Cocoa Touch, but it was missing a crucial capability: the ability to interact with the user. Without that, our application is severely limited in terms of what it can accomplish.
In this chapter, we're going to write a slightly more complex application–sone that will feature two buttons as well as a label, as shown in Figure 3–1. When the user taps either of the buttons, the label's text will change. This may seem like a rather simplistic example, but it demonstrates the key concepts involved in creating interactive iOS apps.