Core Objective-C in 24 Hours by Keith Lee
Approx. 23,590 words.
Published on September 12, 2011.
Core Objective-C in 24 Hours provides a clear and concise overview of the programming language, describes its key features and APIs, and presents recommendations for developing Objective-C programs on the Mac. It is written for readers who want a general understanding of Objective-C technology on the Mac along with developers who want to quickly get started with the language.