Example code to show can NOT use Base* for the array of Sub

ArrayTrap.cpp

#include <iostream>
#include <assert.h>

using namespace std;
class B;
class A
{
public:
	A();
	~A();
	int aa;
};

class B:public A
{
public:
	B();
	~B();
	int bb;
};

A::A()
{
	cout<<"A"<<" ";
	aa=1;
}

A::~A()
{
	cout<<"~A"<<" ";
	aa=-1;
}

B::B()
{
	cout<<"B"<<" ";
	bb=2;
}

B::~B()
{
	cout<<"~B"<<" ";

	bb=-2;
}

int main(int argc, char* argv[])
{
	cout<<"size of A: "<<sizeof(A)<<endl;
	cout<<"size of B: "<<sizeof(B)<<endl;
	A* aarray = new B[10];

	cout<<endl<<endl<<"aa value of A* is:"<<endl;
	for (int i = 0; i < 10; i++)
	{
		cout<<aarray[i].aa<<", ";
	}
	cout<<endl;

	B* baaray = (B*)aarray;
	cout<<endl<<"aa value of B* is:"<<endl;
	for (int i = 0; i < 10; i++)
	{
		cout<<baaray[i].aa<<", ";
	}
	cout<<endl<<endl;

	delete[] aarray;
	cout<<endl<<endl<<"After delete[]"<<endl;

	cout<<endl<<"aa value of A* is:"<<endl;
	for (int i = 0; i < 10; i++)
	{
		cout<<aarray[i].aa<<", ";
	}
	cout<<endl;
	baaray = (B*)aarray;
	cout<<endl<<"aa value of B* is:"<<endl;
	for (int i = 0; i < 10; i++)
	{
		cout<<baaray[i].aa<<", ";
	}
	return 0;
}