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

Pointers to pointers

If we can have a pointer that points to a variable, it should come as no surprise that we have a pointer that points to another pointer, which then points to our desired variable. This is called a double indirection. When using a pointer to a pointer to a variable, we must doubly dereference our starting pointer to get to the desired value. Why might we need to do that?

Consider the following snippet in pointers2.c:

  printf( "address of pDimension = %#lx\n" ,
(unsigned long)&pDimension);

Now, you might have observed that we didn't move this code snippet into theshowInfo()function. That is because if we passed pDimension into the function as a parameter, a new temporary variable would be created and the value of pDimension would be copied into it. We would thus see the address of the function variable, which would be different from the location ofpDimension. We can move it intoshowInfo(), but we will need...