为什么通过基 class 指针初始化派生 class 与通过派生 class 指针初始化不同？

Question

#include <iostream>
using namespace std;

class Base {
public:
        void F(){cout << "Base::F" << endl;};
        virtual void G(){cout << "Base::G" << endl;};
};

class Derived : public Base {
public:
        void F(){cout << "Derived::F" << endl;};
        void G(){cout << "Derived::G" << endl;};
};

int main(){
        Derived *pDerived = new Derived;
        pDerived->F(); //F was redefined
        pDerived->G(); //G was overriden
        Base *pBase = new Derived;
        pBase->F();
        pBase->G();

}

这段代码的输出是：

Derived::F
Derived::G
Base::F
Derived::G

为什么代码没有产生以下输出？

Derived::F
Derived::G
Derived::F
Derived::G

即当派生class对象通过基class指针初始化时，为什么非虚函数的函数定义与通过派生[=]初始化的派生class对象的函数定义不同13=]指针？当我们调用 "new Derived" 时，无论是来自基 class 指针还是派生 class 指针，不应该初始化相同类型的对象吗？

Answer 1

函数F()不是虚函数，这意味着函数调用将被静态调度到pointer/reference静态类型的版本，而不是让它在运行时查找什么确实是动态类型的对象。

如果您确定感兴趣的变体，则可以从指向 Derived 的指针访问相同的函数：

pDerived->Base::F();

为什么通过基 class 指针初始化派生 class 与通过派生 class 指针初始化不同？

Why is initialization of derived class through a base class pointer different from that through a derived class pointer?

c++

inheritance

polymorphism

virtual-functions