In this chapter, you modified RestaurantItem to hold the identifier of a restaurant in the restaurantID property.

You updated ReviewFormViewController and PhotoFilterViewController to save reviews and photos together with a restaurant identifier using Core Data.

You modified RestaurantDetailViewController to load reviews for a particular restaurant based on the restaurant identifier, and displayed them in a collection view. You also calculated and displayed the overall rating for that restaurant. 

Finally, on your own, you modified RestaurantDetailViewController to load photos for a particular restaurant based on the restaurant identifier, and displayed them in a collection view.

You now know how to save and load reviews and photos using Core Data, which you will now be able to implement in your own apps.

You have come to the end of a long journey, and have now finished building your app's primary functionality. All the screens work, and reviews and photos are persistent. Fantastic job!

This concludes Section 3 of this book. In the next part, you'll find out about the cool new features Apple will be introducing in iOS 13 and how to add them to your app, starting with Dark Mode in the next chapter.