20.1 SwiftUI Views
User interface layouts are composed in SwiftUI by using, creating and combining views. An important first step is to understand what is meant by the term “view”. Views in SwiftUI are declared as structures that conform to the View protocol. In order to conform with the View protocol, a structure is required to contain a body property and it is within this body property that the view is declared.
SwiftUI includes a wide range of built-in views that can be used when constructing a user interface including text label, button, text field, menu, toggle and layout manager views. Each of these is a self-contained instance that complies with the View protocol. When building an app with SwiftUI you will use these views to create custom views of your own which, when combined, constitute the appearance and behavior of your user interface.
These custom views will range from subviews that encapsulate a reusable subset of view components (perhaps a secure text...