十三周实验一

#include <iostream> using namespace std;class Vehicle {public: void run() const { cout << "run a vehicle. "<<endl; } //(2) run()为虚函数}; class Car: public Vehicle {public: void run() const {cout << "run a car. "<<endl; } }; class Airplane: public Vehicle {public: void run() const {cout << "run a airplane. "<<endl;} }; int main() {cout<<"(a) 直接用对象访问成员函数: "<<endl;Vehicle v;v.run();Car car; Airplane airplane; car.run();airplane.run();cout<<"(b) 用指向基类的指针访问成员函数: "<<endl;Vehicle *vp;vp=&car;vp->run();vp=&airplane;vp->run();system("pause");return 0;} 

#include <iostream> using namespace std;class Vehicle {public: virtual void run() const { cout << "run a vehicle. "<<endl; } //(2) run()为虚函数}; class Car: public Vehicle {public: void run() const {cout << "run a car. "<<endl; } }; class Airplane: public Vehicle {public: void run() const {cout << "run a airplane. "<<endl;} }; int main() {cout<<"(a) 直接用对象访问成员函数: "<<endl;Vehicle v;v.run();Car car; Airplane airplane; car.run();airplane.run();cout<<"(b) 用指向基类的指针访问成员函数: "<<endl;Vehicle *vp;vp=&car;vp->run();vp=&airplane;vp->run();system("pause");return 0;} 

#include <iostream> using namespace std;class Vehicle {public: virtual void run() const =0; //(2) run()为虚函数}; class Car: public Vehicle {public: void run() const {cout << "run a car. "<<endl; } }; class Airplane: public Vehicle {public: void run() const {cout << "run a airplane. "<<endl;} }; int main() {cout<<"(a) 直接用对象访问成员函数: "<<endl;//Vehicle v;编译器在此行提示错误！//v.run();编译器在此行提示错误！Car car; Airplane airplane; car.run();airplane.run();cout<<"(b) 用指向基类的指针访问成员函数: "<<endl;Vehicle *vp;vp=&car;vp->run();vp=&airplane;vp->run();system("pause");return 0;}