Scope Rules

Scope Rules:

Local variables & Global variables:-

            These are two types of variables.

1.            Local Variables

2.            Global Variables.

a) Local Variables:-

ü  The variables declared inside  a function are known as local variables.  The values of these variables cannot be accessed by any other function.

Eg:-       void sum (int a, int b)

            {

                    int z;

                   z=a+b;

               return (z);

            }

Here z is a Local Variable which is declared in the function sum.  So, the value of z is restricted to the function sum.

Eg prog:-         void main()

{

        int a=1,b=2;    /* local variables */

        printf(“in main( ), a=%d,b=%d”,a,b);

   fun( );

}

void fun()

{       int a=6,b=5;   /* local variables */

         printf(“in fun( ),a=%d,b=%d”,a,b);

}

b)  Global Variables:-

            The variables declared outside the main( ) function are known as global variables.  These variables can be accessed by all the functions of the program.

Eg prog:-        

int a=3,b=4;   /* Global variables */

void main( )

{

   printf(“in main(), a=%d,b=%d”,a,b);

    a++;

     b++;

fun( );

}

void fun( )

{

         printf(“in fun( ),a=%d,b=%d”,a,b);

}