Preprocessor Directives and Macro Examples in C

Macro Examples

Example : A Preprocessor Directives and Macro Examples in C to display the message/value using Macro.

#include <stdio.h>
#define STR "Welcome U All in Codershelpline"
main()
  {	
    printf(STR);
  }

Output :
Welcome U All in Codershelpline

--------------  OR  ---------------

#include <stdio.h>  
#define PI 3.141 
 
void main() 
{  
   printf("%f",PI); 
   getch(); 
}
  
Output :
3.141000

Example : A Preprocessor Directives and Macro Examples in C to find the square value of a given number using Macro.

#include <stdio.h>
# define SQR(y) (y*y)

main()
{
   int num1,result;
   printf("Enter a number to find its square value : ");
   scanf("%d", &num1);
   result = SQR(num1);
   printf("\nThe square of %d is %d", num1, result);
}

Output :
Enter a number to find its square value : 12
The square of 12 is 144

Example : A Preprocessor Directives and Macro Examples in C to find the maximum value of given two numbers using Macro.

#include <stdio.h>
#define MAX(p,q) ((p < q) ? (q):(p))

main()
{
	int num1,num2,result;
   	printf("Enter two number to find maximum value : ");
   	scanf("%d%d", &num1,&num2);
   	result = MAX(num1,num2);
   	printf("\nThe max value from %d and %d is = %d", num1,num2,result);
}

Output :
Enter two number to find maximum value : 12
32
The max value from 12 and 32 is = 32

Example : A Preprocessor Directives and Macro Examples in C to find the maximum value of given three numbers using macro.

#include <stdio.h>
#define MAX(p,q) ((p < q) ? (q):(p))
#define LARGEST(p,q,r) ( MAX(p, q) < r) ? (r): (MAX(p, q))

main()
{
	int num1,num2,num3,result;
   	printf("Enter three number to find largest value : ");
   	scanf("%d%d%d", &num1,&num2,&num3);
   	result = LARGEST(num1,num2,num3);
   	printf("\nThe max value among %d %d and %d is %d", num1,num2,num3,result);
}

Output :
Enter three number to find largest value : 50
20
10

The max value among 50 20 and 10 is 50

Example : A C program to find the area of the square & cube of a given number using Macro.

#include <stdio.h>
# define AREASQUARE(y) (y*y)
# define CUBE(x) (x*x*x)

main()
{
   int num1,result1,result2;
   printf("Enter a number to find its cube and area of square value : ");
   scanf("%d", &num1);
   result1 = AREASQUARE(num1);
   result2 = CUBE(num1);
   printf("\nThe square of %d is %d", num1, result1);
   printf("\nThe square of %d is %d", num1, result2);
}

Output :
Enter a number to find its cube and area of square value : 10

The square of 10 is 100
The square of 10 is 1000

Example : A C program to use macro if-endif statement through an example.

#include <stdio.h>    
#include <conio.h> 
   
#define NUM 15 
 
void main() 
{ 
	#if (NUM<10)  
		printf("The Number is smaller than 10 and is: %d",NUM);  
	#endif  
	  
	#if (NUM==10)  
		printf("The Number is equal to : %d",NUM);  
	#endif
	  
	#if (NUM>10)  
		printf("The Number is greater than 10 and is : %d",NUM);  
	#endif
	
	getch();  
}  

Output :
The Number is greater than 10 and is : 15

Example : A C program to use macro if-else-endif statement through an example.

#include <stdio.h>    
#include <conio.h> 
   
#define NUM 900 
 
void main() 
{ 
	#if (NUM<=700)  
		printf("The Number is smaller or equal than given value and is: %d",NUM);  
	
	#else
		printf("The Number is greater than given value and is : %d",NUM);
		  
	#endif
	
	getch();  
}