Program to show call by reference.

			#include<stdio.h>
			#include<conio.h>
			void main()
			{
			int a,b,*aa,*bb,swap();
			clrscr();
			a=5;
			b=10;
			aa=&a;
			bb=&b;
			printf("value of a= %d & value of b=%d before swap",a,b);
			swap(aa,bb);
			printf("\nvalue of a=%d & b=%d after swap",a,b);
			getch();
			}

			
			int swap(int *x,int *y)
			{
			int temp;
			temp=*x;
			*x=*y;
			*y=temp;
			}
Output:
value of a= 5 & value of b=10 before swap
value of a=10 & b=5 after swap