I realize technique projects can be a little dry, but I hope you can see some real advantages to using GameplayKit randomization over other solutions. Not only does it offer a wider range of functionality (shuffled and Gaussian distributions are awesome!) but it makes your code much simpler, and also has the guarantee of being provably random.
Of course, if you're stuck supporting prior versions of iOS, you'll need to mix and match GameplayKit randomization with calls to
arc4random_uniform() and the like.
It bears repeating that this is only a small slice of what GameplayKit offers. If you haven't already read tutorial 34, you should check it out now - it's a tutorial for GKMinmaxStrategist from GameplayKit that shows you how to create an AI for Four in a Row.
One of the most effective motivators of success is sharing your progress with other people – when you tell folks what you're doing and what you've learned, it encourages you to come back for more, which in turn will help you reach your app development goals faster.
So, now that you've done all the hard work it's time to share your success: tell folks that you've completed this project, either by clicking the button below to start composing a tweet, or by writing your own message from scratch. This will definitely encourage you to keep learning, but it will also help other folks discover my work – thank you!
Paul Hudson is the creator of Hacking with Swift, the most comprehensive series of Swift books in the world. He's also the editor of Swift Developer News, the maintainer of the Swift Knowledge Base, and Mario Kart world champion. OK, so that last part isn't true. If you're curious you can learn more here.