MACROS

A macro is a piece of statements(code) which we provide a name or give that piece of statements a name. so whenever we used that name which we provide to that piece of code in the program, that code get replaced by the contents of the macro.

Advantages of using macros.

• Macro effect the speed of execution of a program. It increase the speed of a execution of a program

-It saves a lot of time.

• It make program shorter in length.

TYPES OF MACROS

• Object-like macros

• function-like macros

  Object-like macros do no havet parameters, whereas function like have parameters.

**SYNTAX OF MACROS**

#define identifier(identifier 1,identifier 2,identifier 3.....identifier n) token-string

#define is used for macro defination. in above syntax of macros contain the token list part, this part is a optional part but it used mainly in every case.

example:- #define area(a) (3.14*(a)*(a))

Here, the argument passed is a. Every time the program encounters area(argument), it will be replace by perimeter(3.14*(argument)*(argument)).

C Program to find area of a circle by macros.

 #include <stdio.h>
    #define Pie 3.1415                       // pie macros
    #define area(a) (Pie*(a)*(a))      // area macros
    int main()
{
        int r;                    
        float area;
        printf("Enter the radius: ");
        scanf("%d",&r);
        area=area(r);
        printf(" Area is=%f",area);
        return 0;
    }

OUTPUT

Enter the radius: 4 
Area is=50.264