Saturday, 2 October 2010

MULTI-LEVEL INHERITANCE




MULTI-LEVEL INHERITANCE:

If a class is derived from a derived class, then the inheritance type is called as multi-level inheritance.
                        
In the above example class A is base class and class B is inherited from class A and class C is a derived class inherited from class B
From the above example we can conclude that class B becomes the base class for class C.This is called as multi-level inheritance.
Syntax:
class <derived class name B>: <access specifier><base class name A>
class <derived class name C>: <access specifier><base class name B>
Example 6:
#include<iostream.h>
#include<conio.h>
class A
{
public:
int a;
void setA(int x)
{
a=x;
}
void showA()
{
cout<<”\nA=”<<a;
}
};
class B: public A
{
public:
int b;
void setB(int x)
{
b=x;
}
void showB()
{
cout<<”\nB=”<<b;
}
};

class C: public B
{
public:
int c;
void setC(int x)
{
c=x;
}
void showC()
{
cout<<”\nC=”<<c;
}
};
void main()
{
A objA;
B objB;
C objC;
clrscr();

//calling class A methods
cout<<”\ncalling class A methods”;
objA.setA(10);
objA.showA();

//calling class B methods
cout<<”\n calling class B methods”;
objB.setA(10);
objB.setB(20);
objB.showA();
objB.showB();

//calling class C methods
cout<<”\ncalling class C methods”;
objC.setB(20);
objC.setC(30);
objC.showB();
objC.showC();
getch();
}


Output
Calling class A methods
A=10
Calling class B methods
A=10
B=20
Calling class C methods
B=20, C=30


Types of Inheritance

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