An object-oriented approach to application development makes programs more intuitive to design, faster to develop, more amenable to modification, and easier to understand. Most object-oriented development environments consist of at least three parts:
A library of objects
A set of development tools
An object-oriented programming language and support library
The Objective-C language is a simple computer language designed to enable sophisticated object-oriented programming. Objective-C is defined as a small but powerful set of extensions to the standard ANSI C language. Its additions to C are mostly based on Smalltalk, one of the first object-oriented programming languages. Objective-C is designed to give C full object-oriented programming capabilities, and to do so in a simple and straightforward way.
For those who have never used object-oriented programming to create applications before, this document is designed to help you become familiar with object-oriented development. It spells out some of the implications of object-oriented design and gives you a flavor of what writing an object-oriented program is really like.
The document is intended for readers who might be interested in:
Learning about object-oriented programming
Finding out about the basis for the Cocoa application framework
Programming in Objective-C
This document introduces the object-oriented model that Objective-C is based upon.
Because this isn’t a document 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 ANSI C that you won’t be hampered if you’re not an experienced C programmer.
Important: This document describes the fundamental concepts that are essential to understanding how to use Objective-C effectively and how to structure a program that uses Objective-C. It does not describe the Objective-C language itself. To learn about the language, see The Objective-C Programming Language.
This document is divided into several chapters:
“Why Objective-C?” explains why Objective-C was chosen as the development language for the Cocoa frameworks.
“Object-Oriented Programming” discusses the rationale for object-oriented programming languages and introduces much of the terminology. It develops the ideas behind object-oriented programming techniques. Even if you’re already familiar with object-oriented programming, you are encouraged to read this chapter to gain a sense of the Objective-C perspective on object-orientation and its use of terminology.
The Objective-C Programming Language describes the Objective-C programming language.
Objective-C Runtime Programming Guide describes how you can interact with the Objective-C runtime.
Objective-C Runtime Reference describes the data structures and functions of the Objective-C runtime support library. Your programs can use these interfaces to interact with the Objective-C runtime system. For example, you can add classes or methods, or obtain a list of all class definitions for loaded classes.
Last updated: 2008-11-19