Compositionclass-A “has-a” class-B
public class Point2D {
public int xloc , yloc ;
public Point2D(){
xloc=yloc =0 ;}
}
. . .
Point2D p5 = new Point2D();
p1.xloc = 10 ;
public class Line2D {
public Point2D p1, p2 ;
public Line2D() {
p1 = new Point2D();
p2 = new Point2D();
}
}
. . .
Line2D ln1 = new Line2D();
ln1.p1 = p5 ;
ln1.p1.xloc = 15 ;