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 sscanf() and sprintf() to convert values into and from strings

Typically, when using sscanf() to interpret a string buffer into values, the string buffer is already known or has been allocated elsewhere. sscanf() converts the string into the desired values, assigning them to variables. The sizes of these variables are known by their data type.

On the other hand, when using sprintf() to convert values into characters, the final output buffer size required is rarely known. We can either exercise great care to allocate a specific array size or, more commonly, we can simply allocate an array that is reasonably larger than expected, ignoring any unused or even unneeded buffer space.

The following program demonstrates the use of sscanf() and sprintf():

#include <stdio.h>
#include <string.h> // for memset

const int bufferSize = 80;

int main( void ) {
int anInteger = -1;
doubleaDouble = -1.0;
int numScanned= 0 , numPrinted = 0;

char sIn[] = ...