Book Image

Mastering Swift 2

By : Jon Hoffman
Book Image

Mastering Swift 2

By: Jon Hoffman

Overview of this book

<p><span id="description" class="sugar_field">At their Worldwide Developer’s conference (WWDC) in 2015, Apple announced Swift 2, a major update to the innovative programming language they first unveiled to the world the year before. Swift 2 features exciting enhancements to the original iteration of Swift, acting, as Apple put it themselves as “a successor to the C and Objective-C languages.” – This book demonstrates how to get the most from these new features, and gives you the skills and knowledge you need to develop dynamic iOS and OS X applications.<br /> </span></p> <p><span id="description" class="sugar_field">Learn how to harness the newest features of Swift 2 todevelop advanced applications on a wide range of platforms with this cutting-edge development guide. Exploring and demonstrating how to tackle advanced topics such as Objective-C interoperability, ARC, closures, and concurrency, you’ll develop your Swift expertise and become even more fluent in this vital and innovative language. With examples that demonstrate how to put the concepts into practice, and design patterns and best practices, you’ll be writing better iOS and OSX applications in with a new level of sophistication and control.</span></p>
Table of Contents (24 chapters)
Mastering Swift 2
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Free Chapter
1
Taking the First Steps with Swift
2
Learning about Variables, Constants, Strings, and Operators
Index

Optional chaining


Optional binding allows us to unwrap one optional at a time, but what would happen if we had optional types embedded within other optional types? This would force us to have optional binding statements embedded within other optional binding statements. There is a better way to handle this by using optional chaining. Before we look at optional chaining, let's see how this would work with optional binding:

class Collar {
    var color: String
    init(color: String) {
        self.color = color
    }
}

class Pet {
    var name: String
    var collar: Collar?
    init(name: String) {
        self.name = name
    }
}

class Person {
    var name: String
    var pet: Pet?
    init(name: String) {
        self.name = name
    }
}

In this example, we begin by defining a Collar class, which has one property defined. This property is named color, which is of the type string. We can see that the color property is not an optional; therefore, we can safely assume that it will always...