Page 198 - DCAP404 _Object Oriented Programming

Unit 9: Inheritance

} Notes

void result::total()
{
tmarks=msub1+msub2+msub3+smarks;
}

void result::display()
{
cout<<“enroll:”<<enroll;
cout<<“\nname:”<<name;
cout<<“\ncourse:”<<course;
cout<<“\nexam type:”<<etype;
cout<<“\ntotal marks:”<<tmarks;

}

void main()
{
clrscr();
result r1;
r1.input();
r1.total();
r1.display();

getch();
}
Self Assessment

Fill in the blanks:
11. Deriving a class from more than one direct base class is called ………………… inheritance.
12. To use multiple inheritance, simply specify each base class (just like in single inheritance),
separated by a……………………. .

9.4 Virtual Base Classes

We have just discussed a situation which would require the use of both multiple and multi level
inheritance. Consider a situation, where all the three kinds of inheritance, namely multi-level,
multiple and hierarchical are involved. Let us say the ‘child’ has two direct base classes ‘parent1’
and ‘parent2’ which themselves has a common base class ‘grandparent’. The child inherits the
traits of ‘grandparent’ via two separate paths. It can also be inherit directly as shown by the
broken line. The grandparent is sometimes referred to as ‘INDIRECT BASE CLASS’. Now, the

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