306a.cpp

C++实训教程

/*
	306a.CPP
	了解继承关系 P——基类，P3D——派生类
	CopyRight by Feng.2003/10, 1997/10
*/
#include <iostream.h>
class P	//平面一个点 Point
{
   protected:
	long x,y;
   public:
	P(long a=0,long b=0) { x=a;y=b;}
	void Disp()
   { cout << "x=" <<x<<"  y="<<y;}
};

class P3d : public P  //空间一点（三维）
{
	long z;
  public:
  	P3d(long a=0,long b=0,long c=0):P(a,b)
  	{z=c;}
	long GetZ(){ return z;}
	void Disp()
	{
		cout <<"x= "<<x <<"  y="<< y
	  		 << "  z="<< z <<endl;
   }
};


main()
{
   P3d p1;
   P3d p2(3,-4);
   p2.Disp();
   p2=p1;
   p2.Disp();
   return 0;
}
/*
x= 3  y=-4  z=0
x= 0  y=0  z=0

*/