point3d.java

清华大学第二版

public class Point3d extends Point{


public int x,y,z;
public Point3d()
{}
public Point3d(int a,int b ,int c)
{
	x=a;y=b;z=c;
	}

	public double distance(){
		return Math.sqrt( x*x + y*y + z*z );
	}
	
	
	public	static void main(String args[]) {
		Point p = new Point(1,1);
		System.out.println("p.distance() = " + p.distance());
		p = new Point3d(1,1,1);
		System.out.println("p.distance() = " + p.distance());
	}
	}