public class Demo6 { public static void main(String[] args) { GeometricObject a = new Circle("red", 1); // Upcasting // GeometricObject a = new Rectangle("red", 1, 2); // Upcasting if ( a instanceof Circle ) System.out.println("a is a Circle"); if ( a instanceof Rectangle ) System.out.println("a is a Rectangle"); if ( a instanceof GeometricObject ) System.out.println("a is a GeometricObject"); } }