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Appendix B

Introduction to Programming with Objective-C

In this appendix, you learn some of the key concepts of computer programming and the fundamentals of the Objective-C language. Objective-C is the language of choice when it comes to iOS programming. It is an object-oriented language and was invented in the early ’80s by Brad Cox.

Essentially, Objective-C is an extension of the C language designed to give it object-oriented capabilities by bringing in concepts from another popular programming language in the ’80s—Smalltalk. Objective-C development coincided with the development of the popular C++ language, thus Objective-C and C++ share many common concepts. A brief timeline of the Objective-C language is shown in Figure B-1.

Figure B-1

Fundamental Programming Concepts

To create anything more than the simplest of iOS applications requires you to know how to write programs. A program is a set of instructions to the device to carry out a specific task, and these instructions are specified using a programming language.

Fundamentally, computers are electronic devices, and only understand a language of 1s and 0s (known as binary language). In the early days of computer programming, programmers would have to provide their instructions in this binary language—a process that was both tedious and error prone.

As time went by, sequences of binary digits were given three-character ...