p8-1.cpp

相当丰富的C++源码

#include<iostream>
#include"Point.h"
using namespace std;

class circle :public point
{
public:
	circle(double r=0,int i=0,int j=0);
	double area();
	void showCircle();
private:
	double radius;
};

circle::circle(double r,int i,int j):point(i,j)
{	radius=r;   }

double circle::area()
{  return 3.14159*radius*radius;   }

void circle::showCircle()
{  //cout<<"圆心为："<<"("<<X<<","<<Y<<")"<<endl;  //错误，不能访问基类的私有成员
   cout<<"圆心为：";
   showXY();
   cout<<"圆半径为："<<radius<<endl;
}