Programming and Problem Solving with Java

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7.When a dialog involves processing input from a field after a button has been

clicked, what part of the code is responsible for reading the field and

processing it? (pp. 394–396)

8.How do you register an event listener with a button? (pp. 387–390)

9.What Java interface does an event listener implement, and in what package is

the interface found? (pp. 387–390)

10.What are the parts of an event loop? (pp. 393–394)

11.Which method provides the string that we use to identify the source of an

event? (pp. 409–411)

Answers

1.A JFramecontains a content pane and the content pane contains user interface elements.2.The button

event handler 3.In the user’s actions and in the event handler 4.actionPerformed

5.private staticJTextField dataField;

dataField = newJTextField( 10 );

outPane.add(dataField);

6.outPane.add(newJLabel("Quick Check"));7.The event handler 8.With the addActionListenermethod

9.ActionListeneris found in java.awt.event.10.Initialization of the loop exit condition and the process, loop

entry, exit condition update, process update, and exit 11.getActionCommand

Exam Preparation Exercises

1.If aand bare intvariables with a= 5 and b= 2, what output does each of the fol-

lowing statements produce?

a.outPane.add(new JLabel("a = "+ a + "b = "+ b));

b.outPane.add(newJLabel("Sum:"+ a + b));

c. outPane.add(newJLabel("Sum: "+ a + b));

d.outPane.add(newJLabel(a / b + " feet"));

2.What does the following application display?

importjava.awt.*;

importjavax.swing.*;

public classExamPrep

{

public static voidmain(String[] args)

{

JFrame out;

Container outPane;

final intLBS = 10 ;

int price;

int cost;

charch;

out = newJFrame();