Constructionsuper() constructor
public class Point3D extends Point2D {
public int zloc ;
public Point3D() { zloc = 0 ; } // implicit call to super();
public Point3D(int x, int y, int z) {
zloc = z ; super(x,y);
// other methods
}
. . .
Point3D my_p2 = new Point3D(3,4,20);