Unit 6 (GUI)

Question 1

Which Java package is used for basic GUI programming?

A) java.util
B) java.awt
C) java.io
D) javax.swing

Answer 1

B) java.awt

Question 2

What does the JOptionPane class primarily use for?

A) Handling database connections
B) Creating simple dialogues
C) Performing file operations
D) Managing threads

Answer 2

B) Creating simple dialogues

Question 3

Which method from JOptionPane is used to display a dialog asking the user to enter some text?

A) showMessageDialog
B) showInputDialog
C) showConfirmDialog
D) showOptionDialog

Answer 3

B) showInputDialog

Question 4

What is the primary purpose of containers in GUI applications?

A) To contain and manage other components
B) To display data in a table format
C) To execute background tasks
D) To provide networking capabilities

Answer 4

A) To contain and manage other components

Question 5

What type of component is a JButton?

A) Container
B) Basic component
C) Layout manager
D) Event handler

Answer 5

B) Basic component

Question 6

What will be the output of the following code snippet?

JOptionPane.showMessageDialog(null, “Hello, world!”);
A) Compiles and displays a message dialog with “Hello, world!”
B) Runtime error
C) Compilation error
D) No output

Answer 6

A) Compiles and displays a message dialog with “Hello, world!”

Question 7

Which layout manager arranges components in a left-to-right flow?

A) BorderLayout
B) GridLayout
C) FlowLayout
D) CardLayout

Answer 7

C) FlowLayout

Question 8

What is true about the JPanel class?

A) It cannot contain other components.
B) It is not a subclass of Container.
C) It uses BorderLayout as its default layout manager.
D) It is commonly used to group components within a frame.

Answer 8

D) It is commonly used to group components within a frame.

Question 9

What is a JFrame?

A) A component that functions as a container for other components.
B) A layout manager.
C) A type of event.
D) A basic GUI component.

Answer 9

A) A component that functions as a container for other components.

Question 10

Which method is used to make a JFrame visible?

A) display()
B) show()
C) setVisible(true)
D) open()

Answer 10

C) setVisible(true)

Question 11

What will happen if two buttons are added to a frame that uses FlowLayout and the frame is resized?

A) The buttons will overlap.
B) The buttons will adjust to maintain the flow from left to right.
C) Only one button will be visible.
D) The buttons will disappear.

Answer 11

B) The buttons will adjust to maintain the flow from left to right.

Question 12

What is the correct way to add a JButton to a JFrame?

A) frame.add(new JButton(“Click Me!”));
B) JButton button = “Click Me!”; frame.add(button);
C) frame.setButton(new JButton(“Click Me!”));
D) JButton button = new JButton(); frame.add(button.setText(“Click Me!”));

Answer 12

A) frame.add(new JButton(“Click Me!”));

Question 13

What does the setForeground method do in a GUI component?

A) Changes the background color of the component.
B) Adjusts the size of the component.
C) Sets the color used to draw the text or graphics within the component.
D) Sets the font of the text within the component.

Answer 13

C) Sets the color used to draw the text or graphics within the component.

Question 14

What will be the output if the following code is executed? Assume the button is clicked by the user.

JButton button = new JButton(“Press me”);
button.addActionListener(e -> System.out.println(“Button pressed!”));
A) “Press me”
B) “Button pressed!”
C) No output
D) Compiles with an error

Answer 14

B) “Button pressed!”

Question 15

What is the primary use of a JLabel?

A) To display editable text fields.
B) To create a clickable button.
C) To display a short text string or an image.
D) To select one option from a set of choices.

Answer 15

C) To display a short text string or an image.

Question 16

How do you create a JCheckBox that is initially checked?

A) JCheckBox checkBox = new JCheckBox(“Check me”, true);
B) JCheckBox checkBox = new JCheckBox(“Check me”); checkBox.setChecked(true);
C) JCheckBox checkBox = new JCheckBox(“Check me”); checkBox.setTrue();
D) JCheckBox checkBox = new JCheckBox(true); checkBox.setText(“Check me”);

Answer 16

A) JCheckBox checkBox = new JCheckBox(“Check me”, true);

Question 17

What is the correct way to group several JRadioButtons so that selecting one will deselect the others?

A) Put them in a JPanel.
B) Add them to a ButtonGroup.
C) Set them in a JFrame.
D) Use a GridLayout.

Answer 17

B) Add them to a ButtonGroup.

Question 18

Which component is typically used for accepting a line of text input from the user?

A) JLabel
B) JTextArea
C) JTextField
D) JPasswordField

Answer 18

C) JTextField

Question 19

Which statement is true about the JComboBox?

A) It allows only fixed set of strings as items.
B) It does not fire any events.
C) It can provide a drop-down list of choices.
D) It is used to toggle between true and false states.

Answer 19

C) It can provide a drop-down list of choices.

Question 20

What happens in Java Swing when you call setSize(300, 300) on a JFrame?

A) The size of the JFrame window is set to 300x300 pixels.
B) A compilation error occurs.
C) A runtime error occurs.
D) The JFrame is minimized.

Answer 20

A) The size of the JFrame window is set to 300x300 pixels.

Question 21

Which of the following is an abstract class in Java GUI programming?
A) JFrame
B) JButton
C) JComponent
D) JLabel

Answer 21

C) JComponent

Question 22

What is a primary purpose of the java.awt.event and java.swing.event packages?
A) To provide layout managers
B) To handle user actions through events
C) To manage UI themes
D) To store data

Answer 22

B) To handle user actions through events

Question 23

What does the getBackground() method do in a GUI component?
A) Returns the current background color of the component
B) Changes the size of the component
C) Gets the text within the component
D) Sets the visibility of the component

Answer 23

A) Returns the current background color of the component

Question 24

What is the default layout manager for JPanel?
A) FlowLayout
B) BorderLayout
C) GridLayout
D) CardLayout

Answer 24

A) FlowLayout

Question 25

How would you add multiple buttons to a JFrame to ensure they appear side by side?
A) Use FlowLayout for the frame
B) Use BorderLayout and add each button to a different border
C) Add each button to a separate JPanel
D) None of the above; buttons automatically align side by side

Answer 25

A) Use FlowLayout for the frame