Unit 4B - Free Response - CookieOrder A

Unit 4B - Free Response - CookieOrder A

Each coding exercise has its own folder. Open its .java file and press Run to try it. Run Tests checks every graded exercise in this lesson at once.

The following is a free response question from 2010. It was question 1 on the exam. You can see all the free response questions from past exams at Past AP CSA Exams.

Question 1. An organization raises money by selling boxes of cookies. A cookie order specifies the variety of cookie and the number of boxes ordered. The declaration of the CookieOrder class is shown below.

public class CookieOrder
{
    /** Constructs a new CookieOrder object */
    public CookieOrder(String variety, int numBoxes)
    {
        /* implementation not shown */
    }

    /**
     * @return the variety of cookie being ordered
     */
    public String getVariety()
    {
        /* implementation not shown */
    }

    /**
     * @return the number of boxes being ordered
     */
    public int getNumBoxes()
    {
        /* implementation not shown */
    }

    // There may be instance variables, constructors, and methods that are not
    // shown.
}

The MasterOrder class maintains a list of the cookies to be purchased. The declaration of the MasterOrder class is shown below.

public class MasterOrder
{
    /** The list of all cookie orders */
    private List<CookieOrder> orders;

    /** Constructs a new MasterOrder object */
    public MasterOrder()
    {
        orders = new ArrayList<CookieOrder>();
    }

    /**
     * Adds theOrder to the master order.
     *
     * @param theOrder the cookie order to add to the master order
     */
    public void addOrder(CookieOrder theOrder)
    {
        orders.add(theOrder);
    }

    /**
     * @return the sum of the number of boxes of all of the cookie orders
     */
    public int getTotalBoxes()
    {
        /* to be implemented in part (a) */
    }

    // There may be instance variables, constructors, and methods that are not
    // shown.
}

Part a. The getTotalBoxes method computes and returns the sum of the number of boxes of all cookie orders. If there are no cookie orders in the master order, the method returns 0.

How to Solve This

These multiple choice questions may help you write your solution.

Check your understanding: What type of loop is best for this problem? — answer it on CS Awesome: https://runestone.academy/ns/books/published/csawesome2/cookieOrderA.html#fr_cookieA_1

Check your understanding: What will you return at the end of this method? — answer it on CS Awesome: https://runestone.academy/ns/books/published/csawesome2/cookieOrderA.html#fr_cookieA_2

Check your understanding: What is wrong with this code?

public int getTotalBoxes()
{
    for (CookieOrder co : this.orders)
    {
      int sum = sum + co.getNumBoxes();
    }
    return sum;
}

Answer it on CS Awesome: https://runestone.academy/ns/books/published/csawesome2/cookieOrderA.html#fr_cookieA_3

Mixed Up Code

Check your understanding: The method getTotalBoxes below contains the correct code for one solution to this problem, but it is mixed up. — answer it on CS Awesome: https://runestone.academy/ns/books/published/csawesome2/cookieOrderA.html#cookieOrderA

Solve Part A

Exercise 1

FRQ Cookie Order Part A: Complete the method getTotalBoxes.

Open the 01-FRQCookieOrderA folder and edit MasterOrder.java. Press Run to try it; Run Tests checks it (3 tests).