Question 1

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

Accepted Answer

To create a window, the JFrame class should be extended since it provides the basic window components, such as title bar, minimize/maximize/close buttons, and borders. The Container class is used to hold and organize other components, while JButton and JTextField are used for creating interactive elements within the window.

Question 2

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 typically found at the top of a window and is not part of the content pane. The content pane is usually the area where the main content of the window, such as labels, text areas, and buttons, is displayed.

Question 3

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

Accepted Answer

The method setVisible is used to display a window in Java. It sets the visibility of the window to true. Options A, B, and D are not valid methods for displaying a window.

Question 4

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

Accepted Answer

Title, width, and height are all required attributes for a window as they determine its size and location on the screen. Color, on the other hand, is an optional attribute used to determine the background color of the window.

Question 5

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" specifically sets the width and height of the window, and the arguments passed in are in the correct order for setting the width to 100 and height to 200. The other choices either have the dimensions in the wrong order or use a method that does not exist (setDims or set).

Question 6

If Shape is a class and you create a new class Rectangle that extends Shape, then Shape is a(n) ____ and Rectangle is a(n) ____.Which word goes in the first blank in the sentence above?
A) subclass
B) superclass
C) inherited class
D) package

Accepted Answer

In this scenario, Shape is the superclass and Rectangle is the subclass. A subclass is a class that inherits properties and methods from a superclass. A superclass, on the other hand, is a class that is inherited from by other classes. Therefore, the correct word for the first blank is "superclass."

Question 7

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 answer of To determine whether two reference variables of...

Question 8

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

Accepted Answer

getText is not a method of the JFrame class. It is a method used for retrieving text from a text component such as a JTextArea or JTextField.

Question 9

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

Accepted Answer

JButton is a component in Java Swing that represents a button. In a typical GUI, buttons like "Calculate" and "Exit" are implemented using JButtons to perform actions when clicked, hence both options are correct.

Question 10

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 specifically used for creating windows. The other options are used for creating different user interface components within the window.

Question 11

Wrapper class objects are mutable.

Accepted Answer

Wrapper class objects in Java, such as Integer, Double, and Character, are immutable, meaning once created, their values cannot be changed.

Question 12

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

Accepted Answer

"extends" is a reserved keyword in Java, meaning it has a specific meaning and cannot be used as a variable name or identifier. "pane," "event," and "inheritance" are not reserved keywords in Java.

Question 13

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

Constructors are special methods that are automatically called when an object of a class is created. They typically initialize the object's instance variables and prepare it for use.

Question 14

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

Both statements assign the value of 8 to the Integer object pointed by x. The first statement directly assigns the value, whereas the second statement creates a new Integer object with the value of 8 and assigns it to x. In both cases, x points to an Integer object with value 8.

Question 15

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

Accepted Answer

Autoboxing is when a primitive data type is automatically converted into its corresponding wrapper class object. In this case, the int value 8 is automatically boxed into an Integer object and assigned to the num variable.

Question 16

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

Accepted Answer

The method equals() of the class Integer can be used to compare the values of two Integer objects for equality.

Question 17

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 in figures, particularly in the context of software or web interfaces, are often used both to get input from the user (such as text fields or input boxes) and to show results or outputs (such as displaying calculation results or messages). This dual functionality supports interactive user experiences.

Question 18

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 19

If Shape is a class and you create a new class Rectangle that extends Shape, then Shape is a(n) ____ and Rectangle is a(n) ____.Which word goes in the second blank of the sentence above?
A) subclass
B) superclass
C) method
D) package

Accepted Answer

Shape is the superclass, and Rectangle, being the class that extends Shape, is the subclass.

Question 20

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 in GUI programs are added directly to the GUI window. Some components, such as menus and toolbars, are added to a container (typically a JMenuBar or JToolBar) that is then added to the GUI window or content pane.

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

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

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

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

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

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

If Shape is a class and you create a new class Rectangle that extends Shape, then Shape is a(n) and Rectangle is a(n) .Which word goes in the first blank in the sentence above?

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 ==.

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

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

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

Wrapper class objects are mutable.

Which of the following is a reserved word in Java?

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

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);

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

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

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

Which class is part of the package java.awt?

If Shape is a class and you create a new class Rectangle that extends Shape, then Shape is a(n) and Rectangle is a(n) .Which word goes in the second blank of the sentence above?

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