Answer:

Array of Goods Objects

Here is a modified testing program that uses an array:

public class Store
{

  public static void main ( String[] args )
  {
    Goods[] inventory =  new Goods[10];
    inventory[0] = new Goods( "bubble bath", 1.40 );
    inventory[1] = new Food ( "ox tails", 4.45, 1500 );
    inventory[2] = new Book ( "Emma", 24.95, "Austin" );
    inventory[3] = new Toy  ( "Leggos", 54.45, 8 );

    inventory[0].display();
    inventory[1].display();
    inventory[2].display();
    inventory[3].display();
  }
}

Since each child class is-a Goods, an array of type Goods[] can be used with any of them. The array inventory has 10 slots, but the program uses only 4 of them, like this:

array picture

As always, each slot of the array is a reference variable which can refer to an object that has been created with a new.

QUESTION 16:

Is each of the classes Toy and Book taxable?