基类派生类实虚函数

using namespace std; class Base { protected: int x; public: Base(int n):x(n){} void display(){ cout << __FUNCTION__ << " Base: " << x << endl; } virtual void display2(){ cout << __FUNCTION__ << " Base: " << x << endl; } }; class Derived: public Base { int y; public: Derived(int m):Base(m),y(m){} void display(){ cout << "Derived: " << y << endl; } virtual void display2(){ cout << __FUNCTION__ << " Derived: " << x << endl; } }; int main(void) { Derived d(2); Base * p = &d; cout << "实函数测试:\n"; p->display(); cout << "虚函数测试:\n"; p->display2(); return 0; }

实函数测试:
display Base: 2
虚函数测试:
display2 Derived: 2