3) Write a program that will interchange two values. Use call by value and call by reference functions.

 source file name: SwapPtr.C

void swap1(int a, int b) // call by value function

{

int t=a;

a=b;

b=t;

printf("\n inside swap1 function values are X=%d and Y=%d", a,b);

}

void swap2(int *a, int *b) // call by pointer function

{

int t=*a;

*a=*b;

*b=t;

printf("\n inside swap2 function values are C=%d and D=%d", *a,*b);

}

void main()

{

int x,y;

int c,d;

clrscr();

printf("Interchange of two variables  program");

printf("\n enter 2 numbers C and D: ");

scanf("%d%d",&c,&d);

printf("\n enter 2 numbers X and Y ");

scanf("%d%d",&x,&y);

swap1(x,y); // call by value function

swap2(&c,&d);  // call by reference or pointer

printf("\n after interchange values are X=%d and Y=%d", x,y);

printf("\n after interchange values are C=%d and D=%d", c,d);

getch();

}

output: