CS 160 Final Sample Solutions

Question One

JRadioButton aButton = new JRadioButton();
JRadioButton bButton = new JRadioButton();

JRadioButton oneButton = new JRadioButton();
JRadioButton twoButton = new JRadioButton();

ButtonGroup group1 = new ButtonGroup();
group1.add( aButton );
group1.add( bButton );

ButtonGroup group2 = new ButtonGroup();
group2.add( oneButton );
group2.add( twoButton );

Question Two

0
2
4
3
1
Intermission
0
2
4
5
3
1

Question Three

numbers = new ArrayList();        // 1 point

numbers.add( new Integer(i) );    // 2 points

int total = 0;                    // 1 point

for (int i = 0; i < numbers.size(); i++)    // 2 points

total += ( (Integer) numbers.get(i) ).intValue();   // 2 points

return total;                     // 1 point

private ArrayList numbers;        // 1 point

Question Four

public class Employee
{

  Employee (double wage)
  {
    this.wage = wage;
    hours = 0;
  }
			        
  public int getHours ()
  {
    return hours;
  }

  public void work (int hoursWorked)
  {
    hours += hoursWorked;
  }

  public double getPay ()
  {
    double result = wage * hours;
    hours = 0;
    return result;
  }

  private double wage;
  private int hours;
}

Question Five

for (int i = 0; i < word.length(); i = i + 4)
{
  System.out.print(word.charAt(i));
}

Question Six

a. unlimited
b. one
c. a method works differently depending on how it is called
d. 5
e. final
f. boolean flag;

Question Seven

1. The user presses a button
2. Assuming that an ActionListener has been implemented and installed
   for that button, the ActionListener is sent the "button press" event
3. The actionPerformed method within the ActionListener is carried out

Question Eight

x = 5
y = 10

Question Nine

public class Food
{
  public double getWeight()
  {
    return weight;
  }

  public void setWeight (double weight)
  {
    this.weight = weight;
  }

  private double weight;
  private String Color;
}

public class Apple extends Food
{
   // whatever
}

public class Banana extends Food
{
   // whatever
}