311.cpp

C++实训教程

//311.cpp
#include <iostream.h>
class APoint
{
   private:		long x,y;
   public:
		APoint(long a=0,long b=0)
   		{ cout << "In APoint()\n"; x=a;y=b;}
		void Disp()	{ cout << "x=" <<x<<"  y="<<y;}
		void Move(long s,long t){x+=s;y+=t;}
};
class Point3d : public APoint
{
	long z;
  public:
	Point3d():APoint() {z=0;}
  	Point3d(long a=0,long b=0,long c=0):APoint(a,b)
  	{ 	cout<<"In Point3d()\n";      z=c;  }
	void Move(long s,long t,long u)
	{	APoint::Move(s,t);	z+=u;}
	
void Disp()
	{APoint::Disp(); 	cout << "  z="<< z <<endl;  }
};
main()
{
   Point3d p2(20,-40);  p2.Disp();Point3d p1(-5);
   p1.Move(-10,3,55);   p1.Disp();   return 0;
}

/*
In APoint()
In Point3d()
x=20  y=-40  z=0
In APoint()
In Point3d()
x=-15  y=3  z=55
*/