Problem of the Day

Friday, May 15, 2026

Problem:

The RandomCookieJar class keeps track of a random number of cookies, described by a String name: "chocolate chip", "sugar", "oatmeal", etc. A partial listing of the RandomCookieJar class is given here.

public class RandomCookieJar
{
    private ArrayList<String> cookies;

    /* constructor and methods not shown */
    
}

The fillJar method is used to add cookies to the jar as described below.

/**
 * Fills the cookie jar with a specified number of cookies selected
 * randomly from a list.
 * @param cookieList an Array of cookies available to fill jar
 * @param amount the total number of cookies to add to the jar
 * PRECONDITION cookieList has at least one type of cookie
 */
public void fillJar(String[] cookieList, int amount)
{
   
    /* missing code */
   
}

Which code should be used to replace /* missing code */ so the method will work as described?

1. 
   

   for (int i = 0; i < cookieList.length; i++)
   {
      cookies.add( cookieList[i] );
   }

2. 
   

   for (int i = 0; i < amount; i++)
   {
      cookies.add(cookieList[ (int) (Math.random() * cookieList.length) ] );
   }

3. 
   

   for (int i = 0; i < amount - 1; i++)
   {
      cookies.add(cookieList[ (int) (Math.random() * cookieList.length) ] );
   }  

4. 
   

   for (int i = 0; i < amount; i++)
   {
      cookies.add(cookieList[ (int) (Math.random() * cookieList.size()) ] );
   }   

5. 
   

   for (int i = 0; i < amount; i++)
   {
      cookies.add(cookieList[ (Math.random() * cookieList.length) ] );
   }

Show solution: