Without any doubt, Swift is the main programming language for developing new applications for Apple developers, but there are many apps on the App store that have been developed using Objective-C. Many of these apps are serving millions of users worldwide. So to build your career, you probably need to be able to read or even write Objective-C codes.
To be honest, Objective-C is not an easy language. As a Swift programmer, I think one of the easiest ways to learn this language, is by reading the book “Objective-C for Swift Developers” Written by Paul Hudson. This book has been written with the assumption that you know Swift. In this book, Everything happens very fast and summarized and you can learn the tips and tricks of the language very soon.
Book Contents
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
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++
I hope you enjoy reading it.