Book Image

Mastering Swift 3 - Linux

By : Jon Hoffman
Book Image

Mastering Swift 3 - Linux

By: Jon Hoffman

Overview of this book

Swift is a modern, fast, and safe programming language created by Apple. Writing Swift is interactive and fun, the syntax is concise yet expressive, and the code runs lightning-fast. Swift’s move to open source has been embraced with open arms and has seen increased adoption in the Linux platform. Our book will introduce you to the Swift language, further delving into all the key concepts you need to create applications for desktop, server, and embedded Linux platforms. We will teach you the best practices to design an application with Swift 3 via design patterns and Protocol-Oriented Programming. Further on, you will learn how to catch and respond to errors within your application. When you have gained a strong knowledge of using Swift in Linux, we’ll show you how to build IoT and robotic projects using Swift on single board computers. By the end of the book, you will have a solid understanding of the Swift Language with Linux and will be able to create your own applications with ease.
Table of Contents (24 chapters)
Mastering Swift 3 - Linux
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
2
Learning About Variables, Constants, Strings, and Operators

Polymorphism with protocols


What we were seeing in the previous examples is a form of polymorphism. The word polymorphism comes from the Greek roots Poly, meaning many, and morphe, meaning form. In programming languages, polymorphism is a single interface to multiple types (many forms). In the previous example, the single interface was the PersonProtocol protocol and the multiple types were any type that conforms to that protocol.

Polymorphism gives us the ability to interact with multiple types in a uniform manner. To illustrate this, we can extend our previous example where we created an array of the PersonProtocol types and loop through the array. We can then access each item in the array using the properties and methods define in the PersonProtocol protocol, regardless of the actual type. Let's see an example of this:

for person in people { 
    print("\(person.firstName) \(person.lastName):  
        \(person.profession)") 
} 

If we ran this example, the output would look similar to this...