The method __________ sets the background color to yellow in JFrame frame.

Question
1 (5 points)


 

The method __________ sets the
background color to yellow in JFrame frame.

Question 1 options:







setBackground(Color.YELLOW)







frame.setBackGround(Color.yellow)







setBackground(Color.yellow)







frame.setBackground(Color.YELLOW)




Question 2 (5 points)

 

What layout manager should you use
so that every component occupies the same size in the container?

Question 2 options:







FlowLayout







any layout







BorderLayout







GridLayout




Question 3 (5 points)

 

Which of the following statements is
for terminating the program when closing the frame?

Question 3 options:







frame.setDefaultCloseOperation(null)







frame.setDefaultCloseOperation(JFrame.TERMINATE_ON_CLOSE)







frame.setDefaultCloseOperation(JFrame.STOP_ON_CLOSE)







frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)




Question 4 (5 points)

 

Which of the following statements
about containers is correct?

Question 4 options:







Both
frames and panels can be placed inside a panel







A panel can be placed inside a panel







A frame
can be placed inside a panel







A frame
can be placed inside a frame




Question 5 (5 points)

 

Which method call puts the string
"Result" into the TextField named result?

Question 5 options:







result.findText()







result.text("Result")







result.newText("Result")







result.setText("Result")




Question 6 (5 points)

 

How many items can be added into a
JComboBox object?

Question 6 options:







0







1







Unlimited







2




Question 7 (5 points)

 

What kind of object is used group
radio buttons?

Question 7 options:







Group







ButtonGroup







JButtonGroup







ContainerGroup




Question 8 (5 points)

 

Which of the following method calls
is used to prevent the user from modifying a text field tf?

Question 8 options:







tf.setUneditable()







tf.setEditable(false);







tf.preventMdification()







tf.setChangable(false);




Question 9 (5 points)

 

When you want to allow the user to
select only one of several choices, which you use?

Question 9 options:







Text
fields







Ordinary
buttons







Radio buttons







Check
boxes




Question 10 (5 points)

 

What is the benefit of using layout
managers?

Question 10 options:







It reduces
the amount of code needed







It defines how components of a window should be
arranged when it is resized







It makes
the program run much faster







It reduces
the amount of memory necessary to store the window components




Question 11 (5 points)

 

Which of the following true about
source and listener objects?

Question 11 options:







Both
objects must be of the same type







The
objects must always be of different types







They must
always be different objects







They can be the same object




Question 12 (5 points)

 

Which of the following statements is
incorrect?

Question 12 options:







A listener
may listen for multiple sources







The
listener object's class must implement the corresponding event-listener
interface







A source object can only have
one listener object







The
listener object must be registered by the source object




Question 13 (5 points)

 

Given the code below, indicate which
statement describes its behavior.



import java.awt.*;

import java.awt.event.*;

import javax.swing.*;



public class Quiz3A extends JFrame implements ActionListener

{

   public Quiz3A()

   {

       JButton okButton = new JButton("OK");

       add(okButton);

   }



   public void actionPerformed(ActionEvent e)

   {

       System.out.println("The OK button is
clicked");

   }



   public static void main(String[] args)

   {

       JFrame frame = new Quiz3A();

       frame.setSize(300, 300);

     
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

       frame.setVisible(true);

   }

}

 

 

Question 13 options:







The actionPerformed method is not executed when
you click the OK button, because no instance of Quiz3A is registered with
okButton







The
program has a compilation error because no listeners are registered for
okButton







The
message The OK button is clicked is displayed when you click the OK button







The
program has a runtime error because no listeners are registered with okButton




Question 14 (5 points)

 

The listener for an button event is
an instance of ________.

Question 14 options:







KeyListener







ActionListener







MouseListener







ItemListener




Question 15 (5 points)

 

Which of the following statements
registers a panel object aPanel as a listener for a button variable aButton?

Question 15 options:







aButton.addActionEventListener(aPanel);







addActionListener(aPanel);







aPanel.addEventListener(aPanel);







aButton.addActionListener(aPanel);




Question 16 (5 points)

 

In the program below, which object
is listening for the events of okButton?



import java.awt.*;

import java.awt.event.*;

import javax.swing.*;



public class Quiz3B extends JFrame implements ActionListener

{

   private JButton okButton = new JButton("OK");



   public Quiz3B()

   {

       add(okButton);

       okButton.addActionListener(this);

   }



   public void actionPerformed(ActionEvent e)

   {

       System.out.println("The OK button is clicked");

   }



   public static void main(String[] args)

   {

       JFrame frame = new Quiz3B();

       frame.setSize(300, 300);

     
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

       frame.setVisible(true);

   }

}

Question 16 options:







okButton







An
anonymous object







frame







JButton




Question 17 (5 points)

 

What is the benefit of using adapter
classes rather than listeners interfaces?

Question 17 options:







It enables
multiple inheritance of classes







It makes it unnecessary to implement unused
event handling methods







It makes
the response time for responding to events much quicker







It makes
it possible to respond to several events at the same time




Question 18 (5 points)

 

In the program below, which object
is listening for the events of okButton?



import java.awt.*;

import java.awt.event.*;

import javax.swing.*;



public class Quiz3C extends JFrame

{

   private JButton okButton = new JButton("OK");



   public Quiz3C()

   {

       add(okButton);

       okButton.addActionListener(

               new ActionListener()

               {

                   @Override

                   public
void actionPerformed(ActionEvent ae)

                   {

                     
 System.out.println("The OK button is clicked");

                   }

               });

   }

   public static void main(String[] args)

   {

       JFrame frame = new Quiz3C();

       frame.setSize(300, 300);

       frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

       frame.setVisible(true);

   }

}

Question 18 options:







An anonymous object







frame







JButton







okButton




Question 19 (5 points)

 

Which of the following will occur if
you fail to register an object as a listener for the click events of a button?

Question 19 options:







The
containing frame will be considered as the default listener







A
compilation error will occur







Nothing will happen when the button is clicked







A class
cast exception will be thrown at run-time




Question 20 (5 points)

 

When a mouse event is generated how
is the location of the click point determined?

Question 20 options:







The event
handler must generate a secondary event to obtain the location







It is
automatically saved as an instance variable in the object of which the mouse
was clicked







It is
obtained by calling a method of the mouse object







It is extracted from the mouse event that is
passed to the event handler




 
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