c++超基础：多态——下、抽象类与虚函数

一、课堂要点

二、使用示例

#include <iostream>using namespace std;class Shape{public:virtual double area() = 0;};class Rectangle : public Shape{double a;double b;public:Rectangle(double a, double b){this->a = a;this->b = b;}virtual double area(){return a * b;}};class Circle: public Shape{double r;public:Circle(double r){this->r = r;}virtual double area(){return 3.14 * r * r;}};void area(Shape *p){cout<<"area: "<<p->area()<<endl;}int main(){Rectangle rectangle(1,2);Circle circle(3);area(&rectangle);area(&circle);return 0;}