022 看上去像多态

#include <iostream>
using namespace std;
class B {
private:
    int nBVal;
public:
    void Print()
    {
        cout << "nBVal=" << nBVal << endl;
    }
    void Fun()
    {
        cout << "B::Fun" << endl;
    }
    B(int n) { nBVal = n; }
};

// 在此处补充你的代码

class D:public B {
private:
    int nDVal;
public:
    
    D(int n):B(3*n),nDVal(n) {}
    void Fun() {
        cout << "D::Fun" << endl;
    }
    void Print() {
        B::Print();
        cout << "nDVal="<< nDVal << endl;
    }
};

int main() {
    B* pb; D* pd;
    D d(4); d.Fun();
    pb = new B(2); pd = new D(8);
    pb->Fun(); pd->Fun();
    pb->Print(); pd->Print();
    pb = &d; pb->Fun();
    pb->Print();
    return 0;
}