TestCircleCylinder.java

public class TestCircleCylinder {
    public static void main(String[] args) {
        Cylinder cy1 = new Cylinder();
        Circle c1 = new Circle();

        System.out.println("Radius is " + cy1.getRadius()
                + ",Height is " + cy1.getHeight()
                + ",Color is " + cy1.getColor()
                + ",Base are is " + cy1.getArea()
                + ",Volume is " + cy1.getVolume());

        System.out.println("Radius is " + c1.getRadius()
                + ",Color is " + c1.getColor()
                + ",Base are is " + c1.getArea());

        // substitute
        Circle c = new Circle();
        Circle c2 = new Cylinder(1.1, 2.2);
        System.out.println(c2.getRadius());// 2.2
        Cylinder cy = new Circle();// error

        // Upcasting and Downcasting
        /*
         * 
         * upcastting - substitution
         * Circle cc=new Cylinder()//it works
         * Circle ccc=new String();//error
         * 
         * Downcasting
         * Circle c=new Cylinder(); //upcast
         * Cyclinder cy = (Cylinder) c; //downcast
         * 
         */

    }

}