用指针输出几何体
#include <iostream>
using namespace std;
class Point
{
public:
Point(double x=0,double y=0);
friend ostream & operator<<(ostream &,const Point &);
protected:
double x,y;
};
Point::Point(double a,double b):x(a), y(b){}
ostream & operator<<(ostream &output,const Point &p)
{
output<<" 点：["<<p.x<<","<<p.y<<"]"<<endl;
return output;
}
class Circle:public Point
{
public:
Circle(double x=0,double y=0,double r=0);
double area ( ) const;
friend ostream &operator<<(ostream &,const Circle &);
protected:
double radius;
};
Circle::Circle(double a,double b,double r):Point(a,b),radius(r) { }
double Circle::area( ) const
{
return 3.14159*radius*radius;
}
ostream &operator<<(ostream &output,const Circle &c)
{
output<<" 圆：Center=["<<c.x<<","<<c.y<<"],r="<<c.radius<<",area="<<c.area( )<<endl;
return output;
}
class Cylinder:public Circle
{
public:
Cylinder (double x=0,double y=0,double r=0,double h=0);
double area( ) const;
friend ostream& operator<<(ostream&,const Cylinder&);
protected:
double height;
};
Cylinder::Cylinder(double a,double b,double r,double h):Circle(a,b,r),height(h) {}
double Cylinder::area( ) const
{
return 2*Circle::area( )+2*3.14159*Circle::radius*height;
}
ostream &operator<<(ostream &output,const Cylinder& cy)
{
output<<" 圆柱：Center=["<<cy.x<<","<<cy.y<<"],r="<<cy.radius<<",h="<<cy.height
<<",area="<<cy.area( )<<endl;
return output;
}
int main( )
{
Cylinder cy1(3.5, 6.4, 5.2, 10);
cout<<cy1<<endl;
Point *p=&cy1;
cout<<"用指向点的指针输出："<<endl;
cout<<(*p);
Circle *c= &cy1;
cout<<"用指向圆的指针输出："<<endl;
cout<<(*c);
Cylinder *cy= &cy1;
cout<<"用指向圆柱的指针输出："<<endl;
cout<<(*cy)<<endl;
return 0;
}
用引用输出几何体
#include <iostream>
using namespace std;
class Point
{
public:
Point(double x=0,double y=0);
friend ostream & operator<<(ostream &,const Point &);
protected:
double x,y;
};
Point::Point(double a,double b):x(a), y(b){}
ostream & operator<<(ostream &output,const Point &p)
{
output<<" 点：["<<p.x<<","<<p.y<<"]"<<endl;
return output;
}
class Circle:public Point
{
public:
Circle(double x=0,double y=0,double r=0);
double area ( ) const;
friend ostream &operator<<(ostream &,const Circle &);
protected:
double radius;
};
Circle::Circle(double a,double b,double r):Point(a,b),radius(r) { }
double Circle::area( ) const
{
return 3.14159*radius*radius;
}
ostream &operator<<(ostream &output,const Circle &c)
{
output<<" 圆：Center=["<<c.x<<","<<c.y<<"],r="<<c.radius<<",area="<<c.area( )<<endl;
return output;
}
class Cylinder:public Circle
{
public:
Cylinder (double x=0,double y=0,double r=0,double h=0);
double area( ) const;
friend ostream& operator<<(ostream&,const Cylinder&);
protected:
double height;
};
Cylinder::Cylinder(double a,double b,double r,double h):Circle(a,b,r),height(h) {}
double Cylinder::area( ) const
{
return 2*Circle::area( )+2*3.14159*Circle::radius*height;
}
ostream &operator<<(ostream &output,const Cylinder& cy)
{
output<<" 圆柱：Center=["<<cy.x<<","<<cy.y<<"],r="<<cy.radius<<",h="<<cy.height
<<",area="<<cy.area( )<<endl;
return output;
}
int main( )
{
Cylinder cy1(3.5, 6.4, 5.2, 10);
cout<<cy1<<endl;
cout<<"使用引用："<<endl;
Point &pRef=cy1;
cout<<"用点的引用输出："<<endl;
cout<<pRef<<endl;
Circle &cRef=cy1;
cout<<"用圆的引用输出："<<endl;
cout<<cRef<<endl;
Cylinder &cyRef=cy1;
cout<<"用圆柱的引用输出："<<endl;
cout<<cyRef<<endl;
return 0;
}
#include <iostream>
using namespace std;
class Point
{
public:
Point(double x=0,double y=0);
friend ostream & operator<<(ostream &,const Point &);
protected:
double x,y;
};
Point::Point(double a,double b):x(a), y(b){}
ostream & operator<<(ostream &output,const Point &p)
{
output<<" 点：["<<p.x<<","<<p.y<<"]"<<endl;
return output;
}
class Circle:public Point
{
public:
Circle(double x=0,double y=0,double r=0);
double area ( ) const;
friend ostream &operator<<(ostream &,const Circle &);
protected:
double radius;
};
Circle::Circle(double a,double b,double r):Point(a,b),radius(r) { }
double Circle::area( ) const
{
return 3.14159*radius*radius;
}
ostream &operator<<(ostream &output,const Circle &c)
{
output<<" 圆：Center=["<<c.x<<","<<c.y<<"],r="<<c.radius<<",area="<<c.area( )<<endl;
return output;
}
class Cylinder:public Circle
{
public:
Cylinder (double x=0,double y=0,double r=0,double h=0);
double area( ) const;
friend ostream& operator<<(ostream&,const Cylinder&);
protected:
double height;
};
Cylinder::Cylinder(double a,double b,double r,double h):Circle(a,b,r),height(h) {}
double Cylinder::area( ) const
{
return 2*Circle::area( )+2*3.14159*Circle::radius*height;
}
ostream &operator<<(ostream &output,const Cylinder& cy)
{
output<<" 圆柱：Center=["<<cy.x<<","<<cy.y<<"],r="<<cy.radius<<",h="<<cy.height
<<",area="<<cy.area( )<<endl;
return output;
}
int main( )
{
Cylinder cy1(3.5, 6.4, 5.2, 10);
Circle *c= &cy1;
Cylinder *cy= &cy1;
cout<<"关于面积："<<endl;
cout<<"用指向圆的指针输出："<<endl;
cout<<c->area()<<endl;
cout<<"用指向圆柱的指针输出："<<endl;
cout<<cy->area()<<endl<<endl;
return 0;
}
