Objective-C Overview

Objective-C is a small, elegant, object-oriented extension to the C language. Strictly speaking, it is a superset of C. You can freely use any valid C code in an Objective-C project. This gives us access to a vast number of third-party libraries, in addition to the Objecitve-C and C frameworks already provided by Apple. This also allows us to switch freely between programming paradigms. We can use object-oriented code (decomposing the problem into objects and methods) in one section, and C-style procedural approach (breaking the program into variables, structures, and functions) in another, using the style that best suits the problem at hand.

Objective-C borrows much of its object syntax from Smalltalk. Smalltalk was one of the earliest object-oriented programs. It was designed to be simple—both easy to implement and easy to learn. Despite its age, Smalltalk remains one of the most innovative program languages on the market. Many modern languages are just now rediscovering techniques originally developed in Smalltalk. Objective-C gains a lot from this heritage: a highly dynamic, very expressive foundation upon which everything else is built.