Symbolic Constants

C Preprocessor: Symbolic Constants

One does not write number literals in a program!

• Inflexible

• Unreadable (a matter of taste though)

• Leads to duplicated code

C Preprocessor replaces symbols with arbitrary strings ⟶ Macros

#define LOWER 0
#define UPPER 300
#define STEP 20

// and later down in the code, all occurences of the token are
// replaces with their values

int start = LOWER;