Exam 10: Interfaces

Consider the following code snippet: public static void main(String[] args) { Final Order myOrder = new Order(); JButton button = new JButton("Calculate"); Final JLabel label = new JLabel("Total amount due"); ) . . Class MyListener implements ActionListener { Public void actionPerformed(ActionEvent event) { ) . . } } } Which of the local variables can be accessed within the actionPerformed method?

What does the MouseAdapter class provide?

Consider the following code snippet: public static void main(String[] args) { Order myOrder = new Order(); JButton button = new JButton("Calculate"); JLabel label = new JLabel("Total amount due"); ) . . Class MyListener implements ActionListener { Public void actionPerformed(ActionEvent event) { Label.setText("Total amount due " + myOrder.getAmountDue()); } } } What is wrong with this code?

To use an interface, a class header should include which of the following?

Consider the following code snippet: public class Demo { Public static void main(String[] args) { Point[] p = new Point[4]; P[0] = new Colored3DPoint(4, 4, 4, Color.BLACK); P[1] = new ThreeDimensionalPoint(2, 2, 2); P[2] = new ColoredPoint(3, 3, Color.RED); P[3] = new Point(4, 4); For (int i = 0; i < p.length; i++) { String s = p[i].toString(); System.out.println("p[" + i + "] : " + s); } Return; } } This code is an example of ____.

To build a user interface that contains graphical components, the components ____.

Which statement about methods in an interface is true?

Consider the following code snippet: public class Inventory implements Measurable { ) . . Public double getMeasure(); { Return onHandCount; } } Why is it necessary to declare getMeasure as public ?

Which of the following statements about interfaces is true?

You wish to detect when the mouse is moved into a graphical component. Which methods of the MouseListener interface will provide this information?

Which of the following statements about interfaces is NOT true?

Consider the following code snippet: public class Inventory implements Measurable { ) . . Double getMeasure(); { Return onHandCount; } } What is wrong with this code?

____ can reduce the coupling between classes.

Which of the following statements about an inner class is true?

____ occurs when a single class has several methods with the same name but different parameter types.

In Java, ____ can be used for callbacks.

The ____ method should be called whenever you modify the shapes that the paintComponent method draws.

Which of the following statements about interfaces is NOT true?

To associate an event listener with a JButton component, you must use the ___ method of the JButton class.

Consider the following code snippet: myImage.add(new Rectangle(10,10,10,10)); This code is an example of using ____.