Objective-C for Swift Developers

Swift is a powerful, modern programming language that will continue to grow over the years ahead. But with over a million existing apps written in Objective-C, you almost certainly need to be able to read, write, and maintain both Swift and Objective-C if you want to score a great job making iOS apps.

This book and video course is designed to help you transfer your existing Swift skills to Objective-C. It assumes you already know how to make iOS apps with Swift, so zero time is wasted explaining Swift techniques. Seriously, if you haven’t already read at least part of either Hacking with Swift or Pro Swift (or worked to a similar level) this book is not for you.

Instead, I’ve written this to help you learn Objective-C as quickly as possible – potentially in as little as four hours if you’re a fast learner.Alongside the book is a video that walks you through creating a complete app from Hacking with Swift, except this time it’s entirely in Objective-C. This means you can literally walk through both projects to see how the code translates, applying your new-found knowledge as you go.

The book follows the same hands-on approach I’ve used in Hacking with Swift and Pro Swift, which means you learn every concept in context rather than as isolated theory. Once you’ve finished the course, you’ll have all the information you need to create your own Objective-C apps or join a company that requires a working knowledge of Objective-C.

What do you get?

You get a complete, hands-on guidebook explaining how key Swift techniques transfer to Objective-C. I’ll be walking you through specific examples like string and array manipulation, blocks vs closures, categories vs extensions, autorelease pools, properties, and more. No time is wasted: I’ve ruthlessly focused everything so you can complete the course as efficiently as possible.

You’ll be learning the latest Objective-C syntax, including generics and nullability, although I’ll be marking places where technology is less likely to be adopted in big business.

The pack also includes a video tutorial where I walk you through creating a complete app from scratch. This uses an example from Hacking with Swift, so you can see a side-by-side comparison between Objective-C and Swift.

What’s in the course?

• What are pointers?
• How do you create strings, arrays, and dictionaries?
• How do blocks differ from closures?
• How do properties differ from ivars?
• What are weak and strong?
• What are categories?
• How do you handle nullability?
• Where does Objective-C++ come in?
• And much more!

Table of Contents

Preface
Introduction
How this book is structured
Real-world projects
Do I love Objective-C?
Before we begin…
Dedication

Overview
Concepts
Basic syntax
Pointers
The size of integers
What is truth?
Format specifiers

Data types
Strings
Numbers
Arrays
Dictionaries
Sets
Generics
NSValue
NSData
NSObject
id and instancetype
NSError
Blocks
Project 1: Hangman

Classes
Introduction to classes
Methods
Properties
Creating objects
Categories and class extensions
Protocols
Nullability
Project 2: Sci-Fi Quotes

Preprocessor
Inside the preprocessor
Defining object-like macros
Metadata macros
Defining function-like macros
Project 3: Swifty Commits

Advanced Topics
Automatic Reference Counting
Autorelease pools
Objective-C++