Book Image

Learn Swift by Building Applications

By : Emil Atanasov, Giordano Scalzo, Emil Atanasov
Book Image

Learn Swift by Building Applications

By: Emil Atanasov, Giordano Scalzo, Emil Atanasov

Overview of this book

Swift Language is now more powerful than ever; it has introduced new ways to solve old problems and has gone on to become one of the fastest growing popular languages. It is now a de-facto choice for iOS developers and it powers most of the newly released and popular apps. This practical guide will help you to begin your journey with Swift programming through learning how to build iOS apps. You will learn all about basic variables, if clauses, functions, loops, and other core concepts; then structures, classes, and inheritance will be discussed. Next, you’ll dive into developing a weather app that consumes data from the internet and presents information to the user. The final project is more complex, involving creating an Instagram like app that integrates different external libraries. The app also uses CocoaPods as its package dependency manager, to give you a cutting-edge tool to add to your skillset. By the end of the book, you will have learned how to model real-world apps in Swift.
Table of Contents (14 chapters)
Adding Interactivity to Your First App


A protocol defines a set of methods, properties, and requirements which should be fulfilled by a class, structure, or enumeration type. The interface defined by the protocol should be implemented by the types, which conform to the protocol. The interface is a public one because all methods and properties in the protocol are public, even though there is no explicit visibility modifier. (For more information, read more about the visibility levels.)

We can think of protocols as types of contracts to be followed. Once you sign a contract (conform to a protocol), then you meet certain requirements and then you can be picked for certain actions.

The definition of a protocol is pretty close to what we know when defining a class, structure, or enumeration type:

protocol CustomContractProtocol {
// list of all requirements (methods or properties)
When picking a name for a...