Derived Class

[coolswathi]

Hi,

I am a newbie and unable to clearly understand how the classes derived from an abstract base class work. My question is :

[3hM2Nwbp]

So long as the derived class isn't abstract, and you provide a visible constructor, then clients will be able to instantiate your class.

class Abstract
{
  public:
   virtual void doSomething(void) = 0;
};

class Derived
 : public Abstract
{
  public:
   virtual void doSomething(void) { } // <-- Should have named it "doNothing"
};

int main()
{
  Derived instance;
  return 0;
}

[coolswathi]

In short I need to override the pure virtual function of the abstract base class with some concrete member function right?

[3hM2Nwbp]

You'll need to override every pure virtual method of the base(s) if you want to instantiate that class.