Question 1

Provide code to generate the following JFrame. Each lettered item is a JButton. Hint: Create several JPanels, each one having two or more JButtons and taken up a portion of the JFrame.

Accepted Answer

JFrame jf = new JFrame( );
JPanel jp1 = new JPanel(new BorderLayout( ));
JPanel jp2 = new JPanel(new FlowLayout( ));
JPanel jp3 = new JPanel(new GridLayout(2, 3));
JButton lab1 = new JButton("A");
JButton lab2 = new JButton("B");
JButton lab3 = new JButton("C");
JButton lab4 = new JButton("D");
JButton lab5 = new JButton("E");
JButton lab6 = new JButton("F");
JButton lab7 = new JButton("G");
JButton lab8 = new JButton("H");
JButton lab9 = new JButton("I");
JButton lab10 = new JButton("J");
JButton lab11 = new JButton("K");
JButton lab12 = new JButton("L");
JButton lab13 = new JButton("M");
jp1.add(lab1, BorderLayout.NORTH);
jp1.add(lab2, BorderLayout.WEST);
jp1.add(lab3, BorderLayout.CENTER);
jp1.add(lab4, BorderLayout.EAST);
jp1.add(lab5, BorderLayout.SOUTH);
jp2.add(lab6);
jp2.add(lab7);
jp3.add(lab8);
jp3.add(lab9);
jp3.add(lab10);
jp3.add(lab11);
jp3.add(lab12);
jp3.add(lab13);
JPanel jp4 = new JPanel(new GridLayout(3, 1));
jp4.add(jp1);
jp4.add(jp2);
jp4.add(jp3);
jf.getContentPane( ).add(jp4);
jf.pack( );
jf.setVisible(True);

Question 2

If classes C1 and C2 both implement an interface Cint, which has a method whichIsIt, and if C1 c = new C1( ); is performed at one point of the program, then a later instruction c.whichIsIt( ); will invoke the whichIsIt method defined in C1.

Accepted Answer

A) True 
 B)False  False

Question 3

Define an interface class that contains two int constants, X = 5 and Y = 10 and one int method called useXY which receives no parameters. Call your interface class XYClass

Accepted Answer

public interface XYClass
{
public final int X = 5;
public final int Y = 10;
public int useXY( );
}

Question 4

Which of the following interfaces would be used to implement a class that represents a group (or collection) of objects?

Accepted Answer

A)   Iterator
B)   Speaker
C)   Comparable
D)   MouseListener
E)   KeyListener

Question 5

It is important to dissect a problem into manageable pieces before trying to solve the problem because

Accepted Answer

A)   most problems are too complex to be solved as a single, large activity
B)   most problems are solved by multiple people and it is easy to assign each piece to a separate person
C)   it is easier to integrate small pieces of a program into one program than it is to integrate one big chunk of code into one program
D)   our first solution may not solve the problem correctly
E)   all of the above

Question 6

It is not possible to test out any single method or class of a system until the entire system has been developed, and so all testing is postponed until after the implementation phase.

Accepted Answer

A) True 
 B)False

Question 7

In general, spending more time in development to ensure better software will

Accepted Answer

A)   shorten testing time
B)   slightly reduce maintenance efforts
C)   slightly increase maintenance efforts
D)   greatly reduce maintenance efforts
E)   not alter the time it takes for any other stage whatsoever

Question 8

Assume that the class Bird has a static method fly( ). If b is a Bird, then to invoke fly, you could do Bird.fly( );.

Accepted Answer

A) True 
 B)False

Question 9

Draw the JFrame as you think it would appear given the following set of code:
JButton jb1 = new JButton("A");
JButton jb2 = new JButton("B");
JButton jb3 = new JButton("C");
JButton jb4 = new JButton("D");
JButton jb5 = new JButton("E");
JButton jb6 = new JButton("F");
JButton jb7 = new JButton("G");
JButton jb8 = new JButton("H");
JButton jb9 = new JButton("I");
JButton jb10 = new JButton("J");
JButton jb11 = new JButton("K");
JButton jb12 = new JButton("L");
JPanel jp1 = new JPanel( );
jp1.add(jb1);
jp1.add(jb2);
jp1.add(jb3);
jp1.add(jb4);
JPanel jp2 = new JPanel(new GridLayout(4, 1));
jp2.add(jb5);
jp2.add(jb6);
jp2.add(jb7);
jp2.add(jb8);
JPanel jp3 = new JPanel(new GridLayout(2, 2));
jp3.add(jb9);
jp3.add(jb10);
jp3.add(jb11);
jp3.add(jb12);
JPanel jp4 = new JPanel(new BorderLayout( ));
jp4.add(jp1, BorderLayout.NORTH);
jp4.add(jp2, BorderLayout.EAST);
jp4.add(jp3, BorderLayout.WEST);
JFrame jf = new JFrame( );
jf.getContentPane( ).add(jp4);
jf.pack( );
jf.setVisible(True);

Accepted Answer

The answer of Draw the JFrame as you think it...

Question 10

Arranging components in a GUI container is accomplished by using which of the following?

Accepted Answer

A)   Layout manager
B)   Listener interface
C)   String array
D)   Event generator
E)   JComboBox

Question 11

Any class can implement an interface, but no classes can implement more than a single interface.

Accepted Answer

A) True 
 B)False

Question 12

Assume a class Foo implements Comparable. Without knowing anything else about the Foo class, write an equal method that returns True if the Foo parameter passed to this Foo is equal to this Foo as determined by using the implementation of Comparable.

Accepted Answer

The answer of Assume a class Foo implements Comparable. Without...

Question 13

To take 2 borders and use one as an outer border and the other as an inner border, you would create a

Accepted Answer

A)   compound border
B)   nested border
C)   split border
D)   border factory
E)   matte border

Question 14

What is wrong with the following message to create a BoxLayout for the JPanel jp?
Jp)setLayout(new BoxLayout(BoxLayout.X_AXIS));

Accepted Answer

A)   X_AXIS is not a valid constant for BoxLayout, it should instead be HORIZONTAL
B)   Aside from X_AXIS, the constructor also requires a Dimension to determine the size of the Box
C)   Aside from X_AXIS, the constructor also needs a command regarding horizontal glue as in createHorizontalGlue( ) 
D)   The BoxLayout constructor is lacking a reference to the container that the BoxLayout manager will govern
E)   There is nothing wrong with it at all

Question 15

A bad programming habit is to build an initial program and then spend a great deal of time modifying the code until it is acceptable. This is known as

Accepted Answer

A)   the prototyping approach
B)   the waterfall model
C)   iterative development
D)   the recursive approach
E)   the build-and-fix approach

Question 16

Write code to create a JPanel with 4 JCheckBox GUI components and two JLabels for output, one that says "Current cost is" and the other that outputs the computed cost based on which of the food items has been selected.

Accepted Answer

The answer of Write code to create a JPanel with...

Question 17

Once we have implemented the solution, we are not done with the problem because

Accepted Answer

A)   the solution may not be the best (most efficient) 
B)   the solution may have errors and need testing and fixing before we are done
C)   the solution may, at a later date, need revising to handle new specifications
D)   the solution may, at a later date, need revising because of new programming language features
E)   all of the above

Question 18

In black-box testing, the tester should already know something about how the program is implemented so that he/she can more carefully identify what portion(s) of the software are leading to errors.

Accepted Answer

A) True 
 B)False

Question 19

It is easier to correct errors found in a program if

Accepted Answer

A)   they are identified early in the development cycle
B)   they are identified during testing
C)   they are identified during program use
D)   they are identified during maintenance
E)   all of the above are equally True, errors are easily corrected in any of these stages

Question 20

Unlike the String class where you must pass a message to an object (instance) of the class, as in x.length( ), in order to use the Math class, you pass messages directly to the class name, as in Math.abs( ) or Math.sqrt( ).

Accepted Answer

A) True 
 B)False

Exam 7: Object-Oriented Design

Provide code to generate the following JFrame. Each lettered item is a JButton. Hint: Create several JPanels, each one having two or more JButtons and taken up a portion of the JFrame.

If classes C1 and C2 both implement an interface Cint, which has a method whichIsIt, and if C1 c = new C1( ); is performed at one point of the program, then a later instruction c.whichIsIt( ); will invoke the whichIsIt method defined in C1.

Define an interface class that contains two int constants, X = 5 and Y = 10 and one int method called useXY which receives no parameters. Call your interface class XYClass

Which of the following interfaces would be used to implement a class that represents a group (or collection) of objects?

It is important to dissect a problem into manageable pieces before trying to solve the problem because

It is not possible to test out any single method or class of a system until the entire system has been developed, and so all testing is postponed until after the implementation phase.

In general, spending more time in development to ensure better software will

Assume that the class Bird has a static method fly( ). If b is a Bird, then to invoke fly, you could do Bird.fly( );.

Arranging components in a GUI container is accomplished by using which of the following?

Any class can implement an interface, but no classes can implement more than a single interface.

Assume a class Foo implements Comparable. Without knowing anything else about the Foo class, write an equal method that returns True if the Foo parameter passed to this Foo is equal to this Foo as determined by using the implementation of Comparable.

To take 2 borders and use one as an outer border and the other as an inner border, you would create a

What is wrong with the following message to create a BoxLayout for the JPanel jp? Jp) setLayout(new BoxLayout(BoxLayout.X_AXIS) ) ;

A bad programming habit is to build an initial program and then spend a great deal of time modifying the code until it is acceptable. This is known as

Write code to create a JPanel with 4 JCheckBox GUI components and two JLabels for output, one that says "Current cost is" and the other that outputs the computed cost based on which of the food items has been selected.

Once we have implemented the solution, we are not done with the problem because

In black-box testing, the tester should already know something about how the program is implemented so that he/she can more carefully identify what portion(s) of the software are leading to errors.

It is easier to correct errors found in a program if

Unlike the String class where you must pass a message to an object (instance) of the class, as in x.length( ), in order to use the Math class, you pass messages directly to the class name, as in Math.abs( ) or Math.sqrt( ).