method overriding virtual or not

Question

What is the difference between:

a)

class base{
   int a;
public:
   virtual int function();
}; 
class derived : public base{
   int b;
public:
   int function();
};

b)

class base{
   int a;
public:
   int function();
};    
class derived : public base{
   int b;
public:
   int function();
};

Why would you use (a) and why would you use (b)?

Is (b) a kind of polymorphism?

score 3 · Accepted Answer · edited May 23 '17 at 12:12

3

a) overrides the method in the base class. b) hides it. b) is not polymorphism.

edited May 23 '17 at 12:12

Community

answered Nov 06 '12 at 17:03

Luchian Grigore

Some people will claim that, when used in templates, `b` can be called static polymorphism... – David Rodríguez - dribeas Nov 06 '12 at 17:27

score 1 · Answer 2 · answered Nov 06 '12 at 17:03

First is overidding while second is method hiding.

First is used for dynamic dispatch and dynamic polymorphism. i.e: To call appropriate method depending on actual type of the object at run-time.

2 Answers2