Preprocessor
At the very start of this book in Chapter 1, Essential Features, we introduced, albeit briefly, the concepts of C preprocessor. Specifically, we talked there about macros, conditional compilation, and header guards.
You will remember that at the beginning of the book, we discussed C preprocessing as an essential feature of the C language. Preprocessing is unique due to the fact that it cannot be easily found in other programming languages. In the simplest terms, preprocessing allows you to modify your source code before sending it for compilation. At the same time, it allows you to divide your source code, especially the declarations, into header files so that you can later include them into multiple source files and reuse those declarations.
It is vital to remember that if you have a syntax error in your source code, the preprocessor will not find the error as it does not know anything about the C syntax. Instead, it will just perform some easy tasks, which typically...
