52- C++ 中的抽象类和接口

1、什么是抽象类

2、

3、问题

4、面向对象中的抽象类

5、

6、抽象类与纯虚函数

7、

#include <iostream>#include <string>using namespace std;class Shape{public:    virtual double area() = 0;};class Rect : public Shape{    int ma;    int mb;public:    Rect(int a, int b)    {        ma = a;        mb = b;    }    double area()    {        return ma * mb;    }};class Circle : public Shape{    int mr;public:    Circle(int r)    {        mr = r;    }    double area()    {        return 3.14 * mr * mr;    }};void area(Shape* p){    double r = p->area();    cout << "r = " << r << endl;}int main(){    Rect rect(1, 2);    Circle circle(10);    area(&rect);    area(&circle);    return 0;}r = 2r = 314

8、抽象类与纯虚函数

9、

10、小结

//利用纯虚函数创建一个接口#include <iostream>#include <string>using namespace std;class Channel{public:    virtual bool open() = 0;    virtual void close() = 0;    virtual bool send(char* buf, int len) = 0;    virtual int receive(char* buf, int len) = 0;};int main(){    return 0;}