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

Learning to experiment with code

Now that we have gotten our basic program to work (woo-hoo!), we can turn our attention to learning how to intentionally break it (ouch!). This is so that we can learn more about what the compiler is trying to tell us. What it is telling us isn't always clear, especially while we are learning.

Once you have mastered the language, there would be little need to do this (yay!). However, while we are learning the language, becoming familiar with the various kinds of compiler error messages is essential and, ultimately, will save us many hours/weeks of debugging, which might have been prevented early on in the iterative program development cycle. Please do not skip this essential step as you learn C as it will save you many hours/weeks.

So, using the full program development cycle outlined earlier, inject the following errors into your source file. When you see the error messages, try to correlate them with what you just did to cause them. After each one, correct the error and recompile it to verify the fix:

  • Remove { from hello2.c. Save it and compile it. What errors does the compiler give?
  • Put { back in its appropriate place and remove }. What errors does the compiler give?
  • There are three other paired punctuation marks: <> and (), which occur twice, and "". What errors does the compiler give when you remove the opening of the pair and the closing of the pair? Put them back after each experiment.
  • Remove ; from either line. What error messages does the compiler give?
  • Comment out the return 0; line. What error messages does the compiler give?
  • Change int main() to int MAIN(). What does the compiler tell you?
  • Similarly, change printf( to printout(. With this error, you should be able to see what linker messages look like.
  • Now, comment out #include <stdio.h>. You should also see linker errors telling you they can't find the printf() function.
  • Return hello2.c to its original state. Compile, run, and verify the program is both correct and complete.

If you get more than 23,000 lines of error messages from the compiler, I would really like to know. Please email me with the details of your experiments.