C #if
Example
#if expression
//code
#endif
Syntax with #else:
Example
#if expression
//if code
#else
//else code
#endif
Syntax with #elif and #else:
Example
#if expression
//if code
#elif expression
//elif code
#else
//else code
#endif
C #if example
Let's explore a basic illustration of utilizing the #if preprocessor directive.
Example
Example
#include <stdio.h>
#include <conio.h>
#define NUMBER 0
void main() {
#if (NUMBER==0)
printf("Value of Number is: %d",NUMBER);
#endif
getch();
}
Output:
Output
Value of Number is: 0
Let's explore a different instance to gain a better grasp of the #if directive.
Example
Example
#include <stdio.h>
#include <conio.h>
#define NUMBER 1
void main() {
clrscr();
#if (NUMBER==0)
printf("1 Value of Number is: %d",NUMBER);
#endif
#if (NUMBER==1)
printf("2 Value of Number is: %d",NUMBER);
#endif
getch();
}
Output:
Output
2 Value of Number is: 1