派生类析构函数发生了什么？

Question

这是我试图理解输出的代码.

class A
    {
    public:

        A();
        ~A(){ cout<<"Destructor Called from A"<<endl;}
        A(int x):Z(x){ cout<<"Constructor Called from A"<<endl; };

    private:
        int Z;
    };

    class B:public A
    {
    public:

        B();
        ~B(){ cout<<"Destructor Called from B"<<endl;}
        B(int x):A(x),Y(x){ cout<<"Constructor Called from B"<<endl; };

    private:
        int Y;
    };

    int main() {

        A *a = new B(10);        
        delete a;

        return 0;
    }

为此,我得到了输出

Constructor Called from A
Constructor Called from B
Destructor Called from A

我的问题是,类的析构函数发生了什么B？对象切片是否在这里起作用？

Answer 1

您需要使超类的析构函数为虚拟:

 class A {
    virtual ~A(){ cout<<"Destructor Called from A"<<endl;}