The Preprocessor

We will study this part of the compilation process in greater detail later (Chapter . However we need some basic information for some C programs.

The Preprocessor accepts source code as input and is responsible for

• removing comments
• interpreting special preprocessor directives denoted by #.

For example

• #include - includes contents of a named file. Files usually called header files. e.g
  • #include <math.h> - standard library maths file.
  • #include <stdio.h> - standard library I/O file
• #define - defines a symbolic name or constant. Macro substitution.
  • #define MAX_ARRAY_SIZE100