Objective-C Programming: The Big Nerd Ranch Guide

So, what is a program?

Now that you have built and run your first program, let’s take a quick look inside to see how it works.

A program is a collection of functions. A function is a list of operations for the processor to execute. Every function has a name, and the function that you just wrote is named main.

When programmers talk about functions, we usually include a pair of empty parentheses. Thus, the main function is referred to as main().

There was another function in your program – printf(). You did not write this function, but you did use it.

To a programmer, writing a function is a lot like writing a recipe card. Like a function, a recipe card has a name and a set of instructions. The difference is that you execute ...