The #define directive assigns the given value to the specified name. All subsequent occurrences of the name are replaced by the value.

#define name value


Name to be defined. This value is any combination of letters, digits, and punctuation that is valid for the C/C++ preprocessor.


Integer, character string, or line of text.


This example assigns values to the names NONZERO and USERCLASS:

#define     NONZERO     1
#define     USERCLASS   "MyControlClass"

Preprocessor Directives