Democlass.java

// This program uses inheritance to extend Box.
class Box {
    double width;
    double height;
    double depth;

    Box(Box ob) { // pass object to constructor
        width = ob.width;
        height = ob.height;
        depth = ob.depth;
    }
    // constructor used when all dimensions specified
    Box(double w, double h, double d) {
        width = w;
        height = h;
        depth = d;
    }
    // constructor used when no dimensions specified
    Box() {

    }
    // constructor used when cube is created
    Box(double len) {
        width = height = depth = len;
    }
    // compute and return volume
    double volume() {
        return width * height * depth;
    }
}

class BoxWeight extends Box {
    double weight; // weight of box
    // constructor for BoxWeight
    BoxWeight()
    {

    }


    BoxWeight(double w, double h, double d, double m) {
        width = w;
        height = h;
        depth = d;
        weight = m;
    }
}
class Democlass {
    public static void main(String args[]) {
        BoxWeight mybox1 = new BoxWeight(10, 20, 15, 34.3);
        BoxWeight mybox2 = new BoxWeight(2, 3, 4, 0.076);
        BoxWeight mybox3 = new BoxWeight();
        double vol;
        vol = mybox1.volume();
        System.out.println("Volume of mybox1 is " + vol);
        System.out.println("Weight of mybox1 is " + mybox1.weight);
        System.out.println();
        vol = mybox2.volume();
        System.out.println("Volume of mybox2 is " + vol);
        System.out.println("Weight of mybox2 is " + mybox2.weight);
    }
}