想知道这个问题的最后一句

Question

定义一个基类Shape，在此基础上派生出Rectangle和Circle，二者都有getArea()函数计算对象的面积。使用Rectangle类创建一个派生类Square

#include

#define pi 3.14

using namespace std;

class Shape{

public:

virtual float getArea(){return 0;}

virtual ~Shape(){}

};

class Rectangle:public Shape{

private:

int lenth,width;

public:

Rectangle(int len,int wid):lenth(len),width(wid){}

float getArea(){return width*lenth;}

};

class Circle:public Shape{

private:

int r;

public:

Circle(int r1):r(r1){}

float getArea(){return pi*r*r;}

};

int main()

{

int a,b,r;

cout<<"Input a,b:";

cin>>a>>b;

cout<<"Input r:";

cin>>r;

Shape *ps;

ps=new Rectangle(a,b);

Shape *pr;

pr=new Circle(r);

cout<<"Rectangle Area:"<<ps->getArea()<<","<<"Circle Area:"<<pr->getArea()<<endl;

delete ps;

delete pr;

return 0;

}

为什么这个派生类square在这个中并没有体现出来，这和题目相符吗？

Answer 1

派生类square我怎么没看到这个

class Square : public Rectangle
{
}