Question

Create a generic class Box with a type parameter that simulates drawing an item at random out of a box. This class could be used for simulating a random drawing. For example, the box might contain Strings representing names written on a slip of paper, or the box might contain Integers representing a random drawing for a lottery based on numeric lottery picks. Create an add() method that allows the user of the class to add an object of the specified type along with size() and isEmpty() method. The former method returns the number of items in the box. Tha latter method determines whether or not the box is empty. Finally, your class should have a drawItem() method that randomly selects an object from the box and returns it (the item is removed from the box). If the user attempts to draw an item out of an empty box, return null. Note that we want the size of the box to be dynamic. In other words, there should not be a hard limit on the size of the box. The user can insert only a few or a large number of items. What is a good option here

Answer 1

Answer:

Check the explanation

Explanation:

//*********** Box.java *********

import java.util.ArrayList;

public class Box<T> {

   ArrayList<T> items=new ArrayList<T>();

   public void add(T item)

   {

       items.add(item);

   }

   public boolean isEmpty()

   {

       return items.isEmpty();

   }

   public T drawItem()

   {

       int randomIndex=(int)(Math.random()*items.size());

       return items.get(randomIndex);

   }

}

//*********** Driver.java *********

public class Driver {

   public static void main(String args[])

   {

       Box<String> partners=new Box();

       Box<Integer> hours=new Box();

       String x="John";

       String y="Tom";

       String z="Annie";

       partners.add(x);

       partners.add(y);

       partners.add(z);

       hours.add(5);

       hours.add(6);

       hours.add(7);

       hours.add(8);

       hours.add(9);

       hours.add(10);

       String study_partner=partners.drawItem();

       int study_hours=hours.drawItem();

       System.out.println("Study partner: "+study_partner);

       System.out.println(("Study hours: "+study_hours));

   }

}

Kindly check the attached image below to see the output.