What Have You Done?
You have written a simple program in Objective-C, including a main() function that created several objects. Some of these objects were instances of LotteryEntry, a class that you created. The program logged some information to the console.
At this point, you have a fairly complete understanding of Objective-C. Objective-C is not a complex language. The rest of the book is concerned with the frameworks that make up Cocoa. From now on, you will be creating event-driven applications, not command-line tools.