define

  Constants and Macros

#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */
 
    #define identifier     replacement_name
    #define identifier(identifier_list)     replacement_name

#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */
 
 
#define ANSWER 42
 
int main(void){
   printf("the answer to life the universe and everything is %d \n", ANSWER );
}

  user@host:~$ ./define 
  the answer to life the universe and everything is 42 
  

#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */
 
#define ANSWER 42
 
int print ( void )
{
   printf("the answer to life the universe and everything is %d \n", ANSWER );
   return 0;
}
 
int main(void)
{
   print();
return 0;
}

  user@host:~$ ./define 
  the answer to life the universe and everything is 42