CODE EXAMPLE FOR C

c ifdef

//INCLUDING BUILT-IN LIBRARIES...
#include <stdio.h>
#include <stdlib.h>
//PRE-DEFINE CONSTANT VALUES...
#define MAXNUM -12    //defining an integer
#define PI 3.1415     //defining a float
#define END "

		Program has ended!!
"   //defining a string
//PRE-DEFINING CONSTANT OPERATIONS...
#define ADD(a, b, c) (a + b + c)    //Operation that will add its 3 parameters

int main(){
    //using other definitions to check if the current device is Windows or UNIX
    #ifdef _WIN32   
        printf("
Windows Operating System Detected
");
    #elif linux
        printf("
UNIX Operating System Detected
");
    #else
        printf("
Operating System could NOT be identified!
");
    #endif
    
    printf("
Using pre-defined values and operations: ");
    printf("
 • MAXNUM: %d",MAXNUM);       //using pre-defined integer
    printf("
 • PI: %f",PI);               //using pre-defined float
    printf("
 • ADD(): %.2f",ADD(2,5,99.5));   //using pre-defined function

    printf(END);    //using pre-defined string
    return 0;
}