circle.h

来自「经典vc教程的例子程序」· C头文件 代码 · 共 25 行

// Fig. 9.4: circle.h 
// Definition of class Circle
#ifndef CIRCLE_H
#define CIRCLE_H

#include <iostream.h>
#include <iomanip.h>
#include "point.h"

class Circle : public Point {  // Circle inherits from Point
   friend ostream &operator<<( ostream &, const Circle & );
public:
   // default constructor
   Circle( double r = 0.0, int x = 0, int y = 0 );

   void setRadius( double );   // set radius
   double getRadius() const;   // return radius
   double area() const;        // calculate area
protected:
   double radius;
};

#endif