Book Image

Swift 3 Object-Oriented Programming - Second Edition

By : Gaston C. Hillar
Book Image

Swift 3 Object-Oriented Programming - Second Edition

By: Gaston C. Hillar

Overview of this book

Swift has quickly become one of the most-liked languages and developers’ de-facto choice when building applications that target iOS and macOS. In the new version, the Swift team wants to take its adoption to the next level by making it available for new platforms and audiences. This book introduces the object-oriented paradigm and its implementation in the Swift 3 programming language to help you understand how real-world objects can become part of fundamental reusable elements in the code. This book is developed with XCode 8.x and covers all the enhancements included in Swift 3.0. In addition, we teach you to run most of the examples with the Swift REPL available on macOS and Linux, and with a Web-based Swift sandbox developed by IBM capable of running on any web browser, including Windows and mobile devices. You will organize data in blueprints that generate instances. You’ll work with examples so you understand how to encapsulate and hide data by working with properties and access control. Then, you’ll get to grips with complex scenarios where you use instances that belong to more than one blueprint. You’ll discover the power of contract programming and parametric polymorphism. You’ll combine generic code with inheritance and multiple inheritance. Later, you’ll see how to combine functional programming with object-oriented programming and find out how to refactor your existing code for easy maintenance.
Table of Contents (17 chapters)
Swift 3 ObjectOriented Programming - Second Edition
Credits
About the Author
Acknowledgement
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Filtering arrays with complex conditions


We can use our new repository to restrict the results retrieved from more complex data. In this case, the getAll method returns an array of Game instances, which we can use with the filter method to retrieve only the games that match certain conditions. The following lines declare a new getWithHighestScoreGreaterThan method for our previously coded GameRepository class. The code file for the sample is included in the swift_3_oop_chapter_07_13 folder:

    open func getWithHighestScoreGreaterThan(score: Int) -> [Game] { 
        return getAll().filter({ (game) in game.highestScore > score }) 
    } 

The getWithHighestScoreGreaterThan method receives a score: Int argument and returns Array<Game>, specified with the [Game] shortcut. The code calls the getAll and filter methods for the result with a closure that specifies the required condition for the games in the array to be returned in the new array. In this case, only the...