{{keywords>wiki library source code example reference}}
====== define ======

    Constants and Macros
<code c>    
#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */

    #define identifier     replacement_name
    #define identifier(identifier_list)     replacement_name
</code>    
===== C Example 1 =====
<code c>
#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 );
}
</code>
==== output example 1 ====

    user@host:~$ ./define 
    the answer to life the universe and everything is 42 
    
===== C Example 2=====
<code c>
#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;
}
</code>
==== output example 2 ====

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