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)
1
Section 1: C Fundamentals
10
Section 2: Complex Data Types
19
Section 3: Memory Manipulation
22
Section 4: Input and Output
28
Section 5: Building Blocks for Larger Programs

Releasing dynamic memory

When we are done with the heap memory we've allocated, we release it with a call to free(). The free() function returns the allocated memory to the available heap pool of memory. This call does not have to occur within the same function where the memory was allocated. The prototype in stdlib.h for free() is as follows:

          void  
          free( void* ptr );

The pointer that's passed to free() must contain a value that originated from one of the calls to malloc(), calloc(), or realloc(). There is no need to cast the void* pointer argument. If ptr is NULL, free() does nothing.

We would release the memory that was allocated in the previous subsection as follows:

free( pCard1 );
free( pCard2 );
free( pHand1 );
free( pHand2 );

These four statements release each block of memory we allocated earlier. Allocated dynamic memory can be freed in any order; it does not have to be freed in the same order...