list of polymorphic objects
- by LivingThing
I have a particular scenario below. The code below should print 'say()' function of B and C class and print 'B says..' and 'C says...' but it doesn't .Any ideas..
I am learning polymorphism so also have commented few questions related to it on the lines of code below.
class A
{
public:
// A() {}
virtual void say() { std::cout << "Said IT ! " << std::endl; }
virtual ~A(); //why virtual destructor ?
};
void methodCall() // does it matters if the inherited class from A is in this method
{
class B : public A{
public:
// virtual ~B(); //significance of virtual destructor in 'child' class
virtual void say () // does the overrided method also has to be have the keyword 'virtual'
{ cout << "B Sayssss.... " << endl; }
};
class C : public A{
public:
//virtual ~C();
virtual void say () { cout << "C Says " << endl; }
};
list<A> listOfAs;
list<A>::iterator it;
# 1st scenario
B bObj;
C cObj;
A *aB = &bObj;
A *aC = &cObj;
# 2nd scenario
// A aA;
// B *Ba = &aA;
// C *Ca = &aA; // I am declaring the objects as in 1st scenario but how about 2nd scenario, is this suppose to work too?
listOfAs.insert(it,*aB);
listOfAs.insert(it,*aC);
for (it=listOfAs.begin(); it!=listOfAs.end(); it++)
{
cout << *it.say() << endl;
}
}
int main()
{
methodCall();
retrun 0;
}