Question 1

To determine whether two reference variables of the Integer type point to the same Integer object, we can use either the method equals of the class Integer or the operator ==.

Accepted Answer

The `equals` method checks for value equality, while the `==` operator checks for reference equality. For Integer objects, `==` may not always work as expected due to Integer caching.

Question 2

Given the declaration, Integer num; The statement num = 8; is known as autoboxing of int type.

Accepted Answer

Autoboxing is the automatic conversion that the Java compiler makes between the primitive type (int) and its corresponding object wrapper class (Integer).

Question 3

A(n) ____ is a method of a class that is automatically executed when an object of the class is created.
A) inheritance
B) package
C) constructor
D) interface

Accepted Answer

A constructor is a special method in a class that is automatically called when an object of the class is instantiated.

Question 4

-Which of the following is NOT found within the content pane?
A) labels
B) title bar
C) text areas
D) buttons

Accepted Answer

The title bar is not found within the content pane.

Question 5

Given the declaration, Integer x; After executing either of the following two statements, x points to an Integer object with value 8: x = 8; x = new Integer(8);

Accepted Answer

In Java, assigning x = 8; autoboxes the primitive int 8 into an Integer object, while x = new Integer(8); explicitly creates a new Integer object with the value 8. Both result in x pointing to an Integer object with the value 8.

Question 6

Which of the following methods is NOT part of the class JFrame?
A) setVisible
B) setSize
C) setTitle
D) getText

Accepted Answer

The method getText is not part of the JFrame class; it is typically associated with text components like JTextField or JTextArea.

Question 7

-Which of the following from the window above is a JButton?
A) Calculate
B) Exit
C) Both Calculate and Exit
D) Perimeter

Accepted Answer

Both "Calculate" and "Exit" are likely to be JButtons, as they are common labels for buttons in a user interface.

Question 8

To create a window, which of the following classes has to be extended?
A) Container
B) JFrame
C) JButton
D) JTextField

Accepted Answer

JFrame is the class that needs to be extended to create a window in Java Swing applications.

Question 9

To compare the values of two Integer objects for equality, we can use the method equals of the class Integer.

Accepted Answer

The Integer class in Java has an equals() method that can be used to compare two Integer objects for equality.

Question 10

Which word goes in the first blank in the sentence above?
A) subclass
B) superclass
C) inherited class
D) package

Accepted Answer

In object-oriented programming, a "superclass" is the class from which other classes inherit properties and methods.

Question 11

-The white areas in the figure above are used to do which of the following?
A) Show output
B) Get input
C) Get input and show results
D) Display a prompt to the user

Accepted Answer

The white areas are used to get input and show results.

Question 12

Wrapper class objects are mutable.

Accepted Answer

Wrapper class objects in Java are immutable, meaning once they are created, their values cannot be changed.

Question 13

-Which of the following statements is NOT true about GUI programs?
A) Every GUI program requires a window.
B) Every window has a title, width, and height.
C) All components are added directly to the GUI window.
D) A layout must be created before components can be added to a content pane.

Accepted Answer

Not all components are added directly to the GUI window; they are often added to containers or panels within the window.

Question 14

To display a window, you must invoke the method ____.
A) displayWindow
B) show
C) setVisible
D) setDisplay

Accepted Answer

The method `setVisible(true)` is used in Java to display a window or make a component visible.

Question 15

Which of the following is a reserved word in Java?
A) extends
B) pane
C) event
D) inheritance

Accepted Answer

"extends" is a reserved word in Java used to indicate that a class is inheriting from a superclass.

Question 16

-The Java class that you use to create windows is ____.
A) JTextField
B) JFrame
C) JButton
D) JLabel

Accepted Answer

JFrame is the Java class that is used to create windows.

Question 17

Which of the following sets the window width to 100 pixels and the height to 200 pixels?
A) setSize(100, 200);
B) setSize(200, 100);
C) setDims(100, 200);
D) set(200, 100);

Accepted Answer

The method setSize(100, 200) correctly sets the window width to 100 pixels and the height to 200 pixels.

Question 18

Which word goes in the second blank of the sentence above?
A) subclass
B) superclass
C) method
D) package

Accepted Answer

Subclass is the correct answer because it is the term used to describe a class that inherits from another class.

Question 19

Which class is part of the package java.awt?
A) JFrame
B) JButton
C) JOptionPane
D) Container

Accepted Answer

Container is part of the java.awt package, while JFrame, JButton, and JOptionPane are part of the javax.swing package.

Question 20

-Which of the following is NOT a required attribute of a window?
A) title
B) width
C) height
D) color

Accepted Answer

Color is not a required attribute for a window, as a window can exist without a specified color. Title, width, and height are typically essential for defining a window's basic properties.

Quiz 6: Graphical User Interface Gui and Object-Oriented Design OOD

To determine whether two reference variables of the Integer type point to the same Integer object, we can use either the method equals of the class Integer or the operator ==.

Given the declaration, Integer num; The statement num = 8; is known as autoboxing of int type.

A(n) ____ is a method of a class that is automatically executed when an object of the class is created.

-Which of the following is NOT found within the content pane?

Given the declaration, Integer x; After executing either of the following two statements, x points to an Integer object with value 8: x = 8; x = new Integer(8);

Which of the following methods is NOT part of the class JFrame?

-Which of the following from the window above is a JButton?

To create a window, which of the following classes has to be extended?

To compare the values of two Integer objects for equality, we can use the method equals of the class Integer.

Which word goes in the first blank in the sentence above?

-The white areas in the figure above are used to do which of the following?

Wrapper class objects are mutable.

-Which of the following statements is NOT true about GUI programs?

To display a window, you must invoke the method ____.

Which of the following is a reserved word in Java?

-The Java class that you use to create windows is ____.

Which of the following sets the window width to 100 pixels and the height to 200 pixels?

Which word goes in the second blank of the sentence above?

Which class is part of the package java.awt?

-Which of the following is NOT a required attribute of a window?