Book Image

Learn C Programming

By : Jeff Szuhay
Book Image

Learn C Programming

By: Jeff Szuhay

Overview of this book

C is a powerful general-purpose programming language that is excellent for beginners to learn. This book will introduce you to computer programming and software development using C. If you're an experienced developer, this book will help you to become familiar with the C programming language. This C programming book takes you through basic programming concepts and shows you how to implement them in C. Throughout the book, you'll create and run programs that make use of one or more C concepts, such as program structure with functions, data types, and conditional statements. You'll also see how to use looping and iteration, arrays, pointers, and strings. As you make progress, you'll cover code documentation, testing and validation methods, basic input/output, and how to write complete programs in C. By the end of the book, you'll have developed basic programming skills in C, that you can apply to other programming languages and will develop a solid foundation for you to advance as a programmer.
Table of Contents (33 chapters)
Section 1: C Fundamentals
Section 2: Complex Data Types
Section 3: Memory Manipulation
Section 4: Input and Output
Section 5: Building Blocks for Larger Programs

Understanding file scope

To declare a variable with file scope, we can declare it anywhere in a source file but outside of any function body. Consider the following code segment from nameSorter.c (Chapter 21, Exploring Formatted Input):

#include <stdio.h>
#include <string.h>
#include <stdbool.h>

const int listMax = 100;
const int stringMax =80;


We have declared the listMax and stringMax variables as external variables outside of any function block. Instead of using those literal values in that program, we used listMax and stringMax whenever we needed those values. It has a scope that is visible throughout this file.

Now, suppose this program was part of a multi-file program. The other source files would not be able to use those variables; their scope is limited to just nameSorter.c. In the next section, we will see how to make these variables accessible to other files.