Book Image

Swift Protocol-Oriented Programming - Fourth Edition

By : Jon Hoffman
Book Image

Swift Protocol-Oriented Programming - Fourth Edition

By: Jon Hoffman

Overview of this book

Protocol-oriented programming is an incredibly powerful concept at the heart of Swift's design. Swift's standard library was developed using POP techniques, generics, and first-class value semantics; therefore, it is important for every Swift developer to understand these core concepts and take advantage of them. The fourth edition of this book is improved and updated to the latest version of the Swift programming language. This book will help you understand what protocol-oriented programming is all about and how it is different from other programming paradigms such as object-oriented programming. This book covers topics such as generics, Copy-On-Write, extensions, and of course protocols. It also demonstrates how to use protocol-oriented programming techniques via real-world use cases. By the end of this book, you will know how to use protocol-oriented programming techniques to build powerful and practical applications.
Table of Contents (11 chapters)

Strong reference cycles

A strong reference cycle is where the instances of two classes hold a strong reference to each other, preventing ARC from releasing either instance. Once again, we are not able to use a Playground for this example, so we need to create an Xcode project. In this project, we start off by creating two classes named MyClass1_Strong and MyClass2_Strong with the following code:

class MyClass1_Strong {
var name = ""
var class2: MyClass2_Strong?
init(name: String) {
self.name = name
print("Initializing class1_Strong with name \(self.name)")
}
deinit {
print("Releasing class1_Strong with name \(self.name)")
}
}
class MyClass2_Strong {
var name = ""
var class1: MyClass1_Strong?
init(name: String) {
self.name = name
print("Initializing class2_Strong with name ...