SwiftUI Essentials – iOS 14 Edition

13. An Introduction to Swift Property Wrappers

Now that the topics of Swift classes and structures have been covered, this chapter will introduce a related topic in the form of property wrappers. Introduced in Swift 5.1, property wrappers provide a way to reduce the amount of duplicated code involved in writing getters, setters and computed properties in class and structure implementations.

13.1 Understanding Property Wrappers

When values are assigned or accessed via a property within a class or structure instance it is sometimes necessary to perform some form of transformation or validation on that value before it is stored or read. As outlined in the chapter entitled “The Basics of Swift Object-Oriented Programming”, this type of behavior ...