The Development Environment

Every object-oriented development environment worthy of the name consists of at least three parts:

• A library of objects and software frameworks and kits
• A set of development tools
• An object-oriented programming language

Cocoa is an extensive library. It includes several software frameworks containing definitions for objects that you can use "off the shelf" or adapt to your program's needs. These include the Foundation Framework, the Application Kit Framework (for building a graphical user interface), and others.

Mac OS X also includes some exceptional development tools for putting together applications. There's Interface Builder, a program that lets you design an application graphically and assemble its user interface on-screen, and Project Builder, a project-management program that provides graphical access to the compiler, the debugger, documentation, a program editor, and other tools.

This book is about the third component of the development environment-the programming language. All Cocoa software frameworks are written in the Objective-C language. To get the benefit of the frameworks, applications must also use either Objective-C or Java.

Objective-C is defined as set of extensions to the C language. It's designed to give C a full capability for object-oriented programming, and to do so in a simple and straightforward way. Its additions to C are few and are mostly based on Smalltalk, one of the first object-oriented programming languages.

This book both introduces the object-oriented model that Objective-C is based upon and fully documents the language. It concentrates on the Objective-C extensions to C, not on the C language itself. There are many good books available on C; this book doesn't attempt to duplicate them.

Because this isn't a book about C, it assumes some prior acquaintance with that language. However, it doesn't have to be an extensive acquaintance. Object-oriented programming in Objective-C is sufficiently different from procedural programming in standard C that you won't be hampered if you're not an experienced C programmer.

© 2001 Apple Computer, Inc.