Hierarchical inheritance

C++ Hierarchical Inheritance Syntax

class A // base class
{
    ..............
};
class B : access_specifier A // derived class from A
{
    ...........
 } ;
 class C : access_specifier A // derived class from A
 {
    ...........
 } ;
 class D : access_specifier A // derived class from A
 {
     ...........
 } ;

C++ Hierarchical Inheritance Example

// hierarchial inheritance.cpp
#include <iostream> 
using namespace std;

class A //single base class
{
    public:
 	int x, y;
 	void getdata()
 	{
   	    cout << "\nEnter value of x and y:\n"; cin >> x >> y;
 	}
};
class B : public A //B is derived from class base
{
    public:
 	void product()
 	{
 	    cout << "\nProduct= " << x * y;
 	}
};
class C : public A //C is also derived from class base
{
    public:
 	void sum()
 	{
        cout << "\nSum= " << x + y;
 	}
};
int main()
{
    B obj1;          //object of derived class B
    C obj2;          //object of derived class C
    obj1.getdata();
    obj1.product();
    obj2.getdata();
    obj2.sum();
    return 0;
}  //end of program

Output

Enter value of x and y:
2
3
Product= 6
Enter value of x and y:
2
3
Sum= 5

Explanation
In this example, there is only one base class A from which two class B and C are derived.

Both derived class have their own members as well as base class members.

The product is calculated in the derived class B, whereas, the sum is calculated in the derived class C but both use the values of x and y from the base class.