1. C, The Foundation of Objective-C

Objective-C is an extension of C. Most of this book concentrates on what Objective-C adds to C, but in order to program in Objective-C, you have to know the basics of C. When you do such mundane things as add two numbers together, put a comment in your code, or use an if statement, you do them the identical way in both C and Objective-C. The non-object part of Objective-C isn’t similar to C, or C-like, it is C. Objective-C 2.0 is currently based on the C99 standard for C.

This chapter begins a two-chapter review of C. The review isn’t a complete description of C; it covers only the basic parts of the language. Topics like bit operators, the details of type conversion, Unicode characters, macros with arguments, and other arcana are not mentioned. It is intended as an aide-memoire for those whose knowledge of C is rusty, or as a quick reference for those who are adept at picking up a new language from context. The following chapter continues the review of C, and treats the topics of declaring variables, variable scope, and where in memory C puts variables. If you are an expert C/C++ programmer, you can probably skip this chapter. (However, a review never hurts. I learned some things in the course of writing the chapter.) If you are coming to Objective-C from a different C-like language, such as Java or C#, you should probably at least skim the material. If your only programming experience is with a scripting language, or if you are a complete beginner, you will probably find it helpful to read a book on C in parallel with this book.