Examples of Macros in C
Below are the programs to illustrate the use of macros in C:
Example 1
The below example demonstrates the use of macros to define LIMIT.
C
// C program to illustrate macros#include <stdio.h>// Macro definition#define LIMIT 5// Driver Codeint main(){ // Print the value of macro defined printf("The value of LIMIT" " is %d", LIMIT); return 0;} |
The value of LIMIT is 5
Example 2
The below example demonstrates the use of macros to find the area of a rectangle.
C
// C program to illustrate macros#include <stdio.h>// Macro definition#define AREA(l, b) (l * b)// Driver Codeint main(){ // Given lengths l1 and l2 int l1 = 10, l2 = 5, area; // Find the area using macros area = AREA(l1, l2); // Print the area printf("Area of rectangle" " is: %d", area); return 0;} |
Area of rectangle is: 50
Explanation
From the above program, we can see that whenever the compiler finds AREA(l, b) in the program it replaces it with the macros definition i.e., (l*b). The values passed to the macro template AREA(l, b) will also be replaced by the statement (l*b). Therefore, AREA(10, 5) will be equal to 10*5.
Macros and its types in C
In C, a macro is a piece of code in a program that is replaced by the value of the macro. Macro is defined by #define directive. Whenever a macro name is encountered by the compiler, it replaces the name with the definition of the macro. Macro definitions need not be terminated by a semi-colon(;).