Java Reference
In-Depth Information
Point(int x, int y)
{
this.x = x;
this.y = y;
}
int getX() { return x; }
int getY() { return y; }
}
class ColoredPoint extends Point
{
private int color;
ColoredPoint(int x, int y, int color)
{
super(x, y);
this.color = color;
}
int getColor() { return color; }
}
class DowncastArrayDemo
{
public static void main(String[] args)
{
ColoredPoint[] cptArray = new ColoredPoint[1];
cptArray[0] = new ColoredPoint(10, 20, 5);
Point[] ptArray = cptArray;
System.out.println(ptArray[0].getX()); // Output: 10
System.out.println(ptArray[0].getY()); // Output: 20
//
System.out.println(ptArray[0].getColor()); // Il-
legal
if (ptArray instanceof ColoredPoint[])
{
ColoredPoint cp = (ColoredPoint) ptArray[0];
System.out.println(cp.getColor());
}
}
}
