Quiz 10

Friday

With a piece of paper, write down your name and answers to the following questions.

1. What method do you use to make a text field, JTextField, read-only?

   1. setChangeable(false)
   2. setEditable(false)
   3. setReadOnly(true)
   4. setUneditable(true)

2. Which of the following is the name of a small box that contains text and appears when the mouse is hovered over a component.

   1. mnemonic
   2. pop-up help
   3. instance message
   4. tool tip

3. Describe what the following program does.

   1. What is displayed in the window?

      The window it titled as “Quiz #10 Question #4”. The window contains a button with text “Button” and a text area.

   2. What happens when the button is pressed?

      When the button is clicked, a new line of text, “Hello”, is appended to the text area.

   import java.awt.FlowLayout;
   import java.awt.event.ActionEvent;
   import java.awt.event.ActionListener;
   
   import javax.swing.JButton;
   import javax.swing.JFrame;
   import javax.swing.JTextArea;
   import javax.swing.SwingUtilities;
   import javax.swing.WindowConstants;
   
   public final class Program implements Runnable {
   	public static void main(String[] args) {
   		SwingUtilities.invokeLater(new Program());
   	}
   
   	@Override
   	public void run() {
   		final MainWindow window = new MainWindow();
   		window.setVisible(true);
   	}
   }
   
   final class MainWindow extends JFrame {
   
   	JButton button = new JButton("Button");
   	JTextArea area = new JTextArea(20, 20);
   
   	public MainWindow() {
   		super("Quiz #10 Question #4");
   
   		this.setLayout(new FlowLayout());
   		this.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
   
   		this.add(this.button);
   		this.add(this.area);
   		this.pack();
   
   		this.button.addActionListener(new ActionListener() {
   			@Override
   			public void actionPerformed(ActionEvent e) {
   				final String oldText = MainWindow.this.area.getText();
   				MainWindow.this.area.setText(oldText + "Hello\n");
   			}
   		});
   	}
   }

Student Performance and Statistics

A histogram of student performance on percentage grades for Quiz 10 on Friday.

A table showing the average performance for each question in Quiz 10 on Friday.