Help me to understand the inheritance

I have this code -

Code:

class A
{

public:
A(int a)
{
cout<<"Base class A"<<a<<endl;
}

}

class B:public class A
{
public:
B(int b,int a):A(int a)
{
cout<<"Derived class B"<<b<<endl;
}

}
class C:public class A
{
public:
C(int c,int a):A(int a)
{
cout<<"Derived class C"<<c<<endl;
}

}

class D:public class C,public class B
{
public:
D(int d,int c,int b):C(int c,int a),B(int b,int a)
{

}

}

main()
{
D d(1,2,3);
}

now here when the objects d(1,2,3) is created. then constructor of D will be called. in that as the class c is initalized first so it will get called but how it gets the value of int a. i am not the getting the flow of the programme. Please help me to understand.

Thanks

Would you understand a simpler example?

How about:

Code:

int main()
{
    A a1(10);
    return 0;
}

Then:

Code:

int main()
{
    B b(1, 10);
    return 0;
}

If you don't understand these, we need to step back a bit.

he's confused by the order of construction in multiple inheritance.

they are constructed the order in which you declare the inheritance chain that determines the order of construction. i.e. you have: "public C, public B" (the class keyword is superfluous here), so the C inheritance branch is constructed, then the B branch


[25] Inheritance -- multiple and virtual inheritance, C++ FAQ Lite