EXERCISE - 7

A) Write a program implementing Friend function.
B) Write a program to illustrate this pointer.
C) Write a program to illustrate pointer to a class.
A) AIM: Write a program implementing FriendFunction.
SOURCE CODE:
#include<iostream>
using namespace std;
class Box
{
    private:
      double length;
    protected:
      double height;
    public:
      double width;
      void getdata();
      friend double volume(Box box);
};
void Box::getdata()
{
    cout<<"Enter length,height and width:"<<endl;
    cin>>length>>height>>width;
}
double volume(Box box)
{
    return box.length*box.height*box.width;
}
int main()
{
    Box b;
    b.getdata();
    cout<<"Volume of box is:"<<volume(b);
}
OUTPUT:
Enter length,height and width:
5
3
2
Volume of box is:30

B) AIM: Write a program to illustrate thispointer.
SOURCE CODE:
#include<iostream>
using namespace std;
class Box
{
    private:
      double length;
    protected:
      double height;
    public:
      double width;
      Box(double length,double height,double width)
      {
          this->length=length;
          this->height=height;
          this->width=width;
      }
      double volume()
      {
          return length*height*width;
      }
};
int main()
{
    double l,h,w;
    cout<<"Enter length,height and width values:"<<endl;
    cin>>l>>h>>w;
    Box b(l,h,w);
    cout<<"Volume of box is:"<<b.volume();
}

OUTPUT:
Enter length,height and width values:
6
4
2
Volume of box is:48

C) AIM: Write a program to illustrate pointer to a class.
SOURCE CODE:
#include<iostream>
using namespace std;
class Box
{
    private:
      double length;
    protected:
      double height;
    public:
      double width;
      Box(double l,double h,double w)
      {
          length=l;
          height=h;
          width=w;
      }
      double volume()
      {
          return length*height*width;
      }
};
int main()
{
    double l,h,w;
    cout<<"Enter length,height and width values:"<<endl;
    cin>>l>>h>>w;
    Box b(l,h,w),*ptr;
    cout<<"Volume of box is:"<<b.volume()<<endl;
    ptr=&b;
    cout<<"Volume of box using pointer is:"<<ptr->volume();
}
OUTPUT:
Enter length,height and width values:
5
4
3
Volume of box is:60
Volume of box using pointer is:60