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

Manipulating characters

The following functions alter a given character:

          digittoint(int c);  // convert char to its number value
int tolower(int c); // convert to lower case
int toupper(int c); // convert to upper case

These functions return the changed character, or the original character if the conversion is not necessary or not valid.

There are also other functions available in ctype.h. They have been omitted for simplicity. Some deal with non-ASCII characters; others deal with eclectic groupings of characters. If you are interested in learning more, you can explore ctype.h on your computer system.

We will see some of these functions in action later in this chapter after we introduce strings. However, before we move on to strings, let's take a first pass at creating the ASCII table shown earlier in this chapter. We will...