MULTIPATH INHERITANCE AND VIRTUAL CLASSES :)

Multipath Inheritance in C++ implements the use of Virtual Classes.

We make the base class 'virtual' by adding the keyword 'virtual' during declaration of Derived class.

#include <iostream>
using namespace std;
class A
{
public:
    int a1;
    A()
    {
        cout<<"Constructor of Base Class A";
    }
};

class B:public virtual A //virtual public A is also OK
{
public:
    int a2;
    B()
    {
        cout<<"\nConstructor of Base Class B";
    }
};

class C:public virtual A
{
public:
    int a3;
    C()
    {
        cout<<"\nConstructor of Class C";
    }
};

class D:public B,public C
{
public:
    int a4;
    D()
    {
        cout<<"\nConstructor of Derived Class D\n\n";
    }
};
int main()
{
    D obj;
    obj.a1=10;
    obj.a2=20;
    obj.a3=30;
    obj.a4=40;
    cout<<"a="<<obj.a1;
    cout<<"\nb="<<obj.a2;
    cout<<"\nc="<<obj.a3;
    cout<<"\nd="<<obj.a4;
    return 0;
}