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 "\n\n\t\tProgram has ended!!\n" //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("\nWindows Operating System Detected\n"); #elif linux printf("\nUNIX Operating System Detected\n"); #else printf("\nOperating System could NOT be identified!\n"); #endif printf("\nUsing pre-defined values and operations: "); printf("\n • MAXNUM: %d",MAXNUM); //using pre-defined integer printf("\n • PI: %f",PI); //using pre-defined float printf("\n • ADD(): %.2f",ADD(2,5,99.5)); //using pre-defined function printf(END); //using pre-defined string return 0; }