For the More Curious: View Controller Relationships
The relationships between view controllers are important for understanding where and how a view controller’s view appears on the screen. Overall, there are two different types of relationships between view controllers: parent-child relationships and presenting-presenter relationships. Let’s look at each one individually.
Parent-child relationships are formed when using view controller containers. Examples of view controller containers are UINavigationController, UITabBarController, and UISplitViewController (which you will see in Chapter 22). You can identify a view controller container because it has a viewControllers property that is an array ...