Programming in Objective-C, Fifth Edition

Your First iPhone Application

The first application shows how you can put a black-colored window on the iPhone’s screen, allow for the user to press a button, and then display some text in response to the pressing of that button.

Note

The second application is more fun! You use the knowledge gained from your first application to build a simple calculator that does operations with fractions. You can use your Fraction class that you worked with earlier in the book, as well as a modified Calculator class. This time, your calculator needs to know how to work with fractions.

Let’s dive right into the first program. This chapter does not cover all the details; as noted, there’s simply not enough space to do that here. Instead, we walk you through ...