Organizing your code

As your programs become more complex, you will use extensions (covered in Chapter 8, Protocols, Extensions, and Error Handling) to organize your code. Extensions can help you make your code more readable and avoid clutter.

In this section, you will organize four classes: ExploreViewController, RestaurantListViewController, LocationViewController, and MapViewController. You will then segregate blocks of related code using extensions. You'll begin with the ExploreViewController class in the next section.

Refactoring the ExploreViewController class

In this section, you will divide the code in ExploreViewController.swift into distinct sections using extensions. Follow these steps:

1. Click ExploreViewController.swift in the Project navigator. After the final curly brace, add the following:

   // MARK: Private Extension
   private extension ExploreViewController {
   // code goes here
   }
   // MARK: UICollectionViewDataSource
   extension ExploreViewController: UICollectionViewDataSource...