test1.cpp

这我们老师对是面向对象程序设计（清华大学出版社）一书制作的PPT

#include <iostream.h>
#include <math.h>
class circle
{ 
private:
    int x,y;
	int r;
public:
	circle(int ,int ,int );
	circle(circle&);
	~circle(){}
	double area();
	circle mirrorx();
	void display();
};
circle::circle(int x1,int y1,int r1):x(x1),y(y1),r(r1){}
circle::circle(circle& c)
{
	x=c.x;y=c.y;r=c.r;
}
double circle::area(){return 3.1416*r*r;}
circle circle::mirrorx(){return circle(x,-y,r);}
void circle::display()
{cout<<"圆心："<<'('<<x<<','<<y<<')'<<endl;
 cout<<"半径："<<r<<endl;
}
void main()
{
	circle s(1,2,10);
	s.display();
	cout<<s.area()<<endl;
	circle s1=s.mirrorx();
	s1.display();
}