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

Using explicit type conversion – casting

If we rely on implicit casting, our results may go awry or we may get unexpected results. To avoid this, we can cause an explicit, yet temporary, type change. We do this by casting. When we explicitly cast a variable to another type, its value is temporarily converted into the desired type and then used. The type of the variable and its value does not change.

Any expression can be prefixed by (type) to change its explicit type to the indicated type for the lifetime of the expression. This lifetime is typically a single statement. The explicit type is never changed, nor is the value stored in that explicitly typed variable. An example of this is given in the following program, casting.c:

#include <stdio.h>

int main( void ) {
int numerator = 33;
int denominator = 5;
double result = 0.0;

result = numerator / denominator;
printf( "Truncation: %d / %d = %.2g\n" ,
numerator , denominator...