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

Custom initializers


Initializers are called when we initialize a new instance of a particular type (class or structure). Initialization is the process of preparing an instance for use. The initialization process can include setting initial values for stored properties, verifying resources, such as web services, files, and so on are available, or setting up the UI properly. Initializers are generally used to ensure that the instance of the class or structure is properly initialized prior to first use.

Initializers are special methods that are used to create a new instance of a type. We define an initializer exactly as we would define other methods, but we must use the init keyword as the name of the initializer to tell the compiler that this method is an initializer. In its simplest form, the initializer does not accept any arguments. Let's look at the syntax used to write a simple initializer:

init() {
  //Perform initialization here
}

This format works for both classes and structures. By default...