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

Memory management


As I mentioned at the start of this chapter, structures are value types and classes are reference types. What this means is that when we pass an instance of a structure within our application, such as a parameter of a method, we create a new instance of the structure in the memory. This new instance of the structure is only valid while the application is in the scope where the structure was created. Once the structure goes out of scope, the new instance of the structure is destroyed and the memory is released. This makes memory management of structures pretty easy and somewhat painless.

Classes, on the other hand, are of the reference type. This means that we allocate the memory for the instance of the class only once when it is initially created. When we want to pass an instance of the class within our application, as either a function argument or by assigning it to a variable, we really pass a reference to where the instance is stored in the memory. Since the instance...