Absolute Beginner's Guide to Programming, Third Edition

C Functions

C is built on a foundation of functions—both those functions that you write and the functions supplied by C. The next two sections should help you understand the nature of C functions.

Using Built-In Functions

Unlike just about every other programming language in the world, C has no input or output statements. Look through Table 13.1 once more. You don't see a Print statement or anything else that might be considered an I/O statement.

C performs all its I/O through functions that your C compiler provides. By letting the compiler makers implement I/O in functions, the C language is highly portable, meaning that a C program that runs on one kind of computer should run on any other computer than is capable of running C programs. A C ...