Section 1: Objective-C and the Cocoa Frameworks

This is a book about writing software for Mac OS X using the Cocoa frameworks. As far as the typical Cocoa developer can tell from looking at the Cocoa headers, the Cocoa frameworks are written entirely in the Objective-C programming language. Likewise, the application that forms the heart of this book is written almost exclusively in Objective-C.

Although Objective-C was inspired by the object-oriented concepts of the Smalltalk language, Objective-C is in fact the C language with a very small amount of object-oriented syntax grafted onto it. Objective-C is a strict superset of C, which means that the Objective-C compiler can compile all proper C programs. You will see as you progress through this book that you must frequently use plain-old C syntax in Objective-C programs.

To use this book, you must already know C as well as Objective-C. You can write Cocoa applications using other languages, such as C++, Ruby, Python, and even AppleScript. However, the headers, the documentation, and almost all of the example code you will rely on as a Cocoa developer are written in Objective-C, and to read and write Objective-C code, you have to know how to read and write C code.

This book will not teach you the ins and outs of C or even Objective-C. For that, you must turn to other books. The book does, however, begin with this short section outlining what you need to learn about C, Objective-C, and the Cocoa frameworks before you get started, and how you can go about acquiring that knowledge with minimum effort.