QUIZ

CHAPTER 11

Your Name:


11.1 Reading a String value s from a Textfield t is done with

(a) s = t.readString();
(b) s = readString(t);
(c) s = t.getText();
(d) t.getText(s);

11.2 If the Traffic program, if there is to be a new light with a green arrow on it, what statement(s) would be needed to add it to the GUI display, without activating it?

(a) buttons.add(walkButton);
(b) walkButton = new Button("Walk"); buttons.add(walkButton);
(c) walkButton = new Button("Walk");
(d) buttons.add (new Button("Walk"));

11.3 The best way to control the sequence in which events on certain components occur is to

(a) set all but the required component invisible
(b) set all but the required component disabled
(c) define boolean variables which are set and checked at appropriate points
(d) put each of the components in a separate panel

11.4 What event is caused by typing into a TextField?

(a) TextEvent
(b) ActionEvent
(c) FieldEvent
(d) MouseClickedEvent

11.5 What is the method used in ActionPerformed to decide what kind of event has occurred?

(a) getEvent()
(b) getSource()
(c) getText()
(d) getAction()

11.6 An event, in Java terms, is

(a) an object
(b) a class
(c) a variable
(d) a component

11.7 When a new Frame is constructed, it appears on the screen

(a) immediately
(b) when setVisible(true) is executed
(c) at the end of the constuctor
(d) whenever the paint method is executed

11.8 A statement such as

closeButton.addActionListener(this)

can best be interpreted as meaning:

store a reference to the current object with closeButton so that an ActionEvent on closeButton will activate the actionPerformed method in the current object
store a reference to the current object with amountField so that the ActionListener will be called when closeButton is pushed
store a reference to closeButton with the actionListener so that close Button's event handler can be called when it is pushed
store a reference to closeButton with the the current object so that the ActionListener can call this object's event handler when closeButton is pushed

11.9 We did not need a hash table in the converter program because the data were stored instead in

(a) an array
(b) the Swing components
(c) the file
(d) a linked list

11.10 In the Till program, to turn a selected product button green when it is pushed, we would use:

(a) itemButtons[select].setBackground(green);
(b) itemButtons[i].setBackground(green);
(c) (Color.green) itemButtons[select];
(d) itemButtons[select].setBackground(Color.green);