Book Image

Learn C Programming - Second Edition

By : Jeff Szuhay
Book Image

Learn C Programming - Second Edition

By: Jeff Szuhay

Overview of this book

The foundation for many modern programming languages such as C++, C#, JavaScript, and Go, C is widely used as a system programming language as well as for embedded systems and high-performance computing. With this book, you'll be able to get up to speed with C in no time. The book takes you through basic programming concepts and shows you how to implement them in the C programming language. Throughout the book, you’ll create and run programs that demonstrate essential C concepts, such as program structure with functions, control structures such as loops and conditional statements, and complex data structures. As you make progress, you’ll get to grips with in-code documentation, testing, and validation methods. This new edition expands upon the use of enumerations, arrays, and additional C features, and provides two working programs based on the code used in the book. What's more, this book uses the method of intentional failure, where you'll develop a working program and then purposely break it to see what happens, thereby learning how to recognize possible mistakes when they happen. By the end of this C programming book, you’ll have developed basic programming skills in C that can be easily applied to other programming languages and have gained a solid foundation for you to build on as a programmer.
Table of Contents (38 chapters)
1
Part 1: C Fundamentals
10
Part 2: Complex Data Types
19
Part 3: Memory Manipulation
22
Part 4: Input and Output
28
Part 5: Building Blocks for Larger Programs

Understanding variable-length arrays

A Variable-Length Array (VLA) is an array whose size is not known until runtime. The first set of arrays declared earlier have fixed length declarations. The second set of arrays are VLA declarations. A VLA declaration is like a fixed-length declaration, except that the array size is specified by a non-constant expression. Here, non-constant refers to a non-literal variable value.

Remember that a const type is a variable whose value is determined at runtime, so even though it cannot be changed once initialized, it is still considered a variable and not a literal constant. When a VLA declaration is encountered, the size expression is evaluated and the array is created with the resultant length. This length must be a positive integer. Once created, the size of a VLA is fixed and cannot change, just as with constant-length arrays.

So, note that the variable in a VLA means that the array size is defined by some variable value and not that the...