Tutorials

2. Call by address

In this, we passed addresses instead of values and function pointers accept addresses and pointing to the actual values.

e.g:

#include<iostream.h>
#include<conio.h>
void swap(int *,int *);
void main()
{
 int a,b;
 clrscr();
 cout<<"Enter values for a ";
 cin>>a;
 cout<<"Enter values for b ";
 cin>>b;
 swap(&a,&b);
 cout<<"After swap a = "<<a<<" and b = "<<b;
 getch();
}
void swap(int *p,int *q)
{
 int temp;
 temp=*p;
 *p=*q;
 *q=temp;
cout<<"After swap a = "<<*p<<" and b = "<<*q;
}

O/P

Enter value for a 4
Enter value for b 5
After swap a = 5 and b =4