Explain the concept of pointer to derived classes.

Explain the concept of pointer to derived classes. 
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1 Answer

Answer :

Pointer to derived class: Pointers can be used to point to the base class objects and objects of derived class. Pointers to objects of base class are type-compatible with pointers to objects of a derived class. Single pointer variable can be made to point objects belonging to different classes. If B is base class and D is derived class then pointer declared as a pointer to B can also be a pointer to D.

Example:

B *cptr; // pointer of base class

B b;//Base object

D d;// Derived object

cptr=&b; //cptr stores address of object b of base class

cptr=&d; //cptr stores address of object d of derived class 

Using cptr, pointer of base class type, we can access only those members which are inherited from B and not the members that originally belong to D.In case a member of D has the same name as one of the members of B,then any reference to that member by cptr will always access the base class member. 
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