QuizProgram source code:
import
java.awt.*;
import
java.awt.event.*;
import
javax.swing.*;
import
javax.swing.event.*;
import
java.util.*;
class Quiz extends JFrame implements
ActionListener{
JPanel panel;
JPanel panelresult;
JRadioButton choice1;
JRadioButton choice2;
JRadioButton choice3;
JRadioButton choice4;
ButtonGroup bg;
JLabel lblmess;
JButton btnext;
String[][] qpa;
String[][] qca;
int qaid;
HashMap<Integer, String> map;
Quiz(){
1 initializedata();
2 setTitle("Quiz
Program");
3 setDefaultCloseOperation(EXIT_ON_CLOSE);
4 setSize(430,350);
5 setLocation(300,100);
6 setResizable(false);
7 Container
cont=getContentPane();
8 cont.setLayout(null);
9 cont.setBackground(Color.GRAY);
10 bg=new ButtonGroup();
11 choice1=new
JRadioButton("Choice1",true);
12 choice2=new
JRadioButton("Choice2",false);
13 choice3=new
JRadioButton("Choice3",false);
14 choice4=new
JRadioButton("Choice4",false);
15 bg.add(choice1);
16 bg.add(choice2);
17 bg.add(choice3);
18 bg.add(choice4);
19 lblmess=new
JLabel("Choose a correct anwswer");
20 lblmess.setForeground(Color.BLUE);
21 lblmess.setFont(new
Font("Arial", Font.BOLD, 11));
22 btnext=new
JButton("Next");
23 btnext.setForeground(Color.GREEN);
24 btnext.addActionListener(this);
25 panel=new JPanel();
26 panel.setBackground(Color.LIGHT_GRAY);
27 panel.setLocation(10,10);
28 panel.setSize(400,300);
29 panel.setLayout(new
GridLayout(6,2));
30 panel.add(lblmess);
31 panel.add(choice1);
32 panel.add(choice2);
33 panel.add(choice3);
34 panel.add(choice4);
35 panel.add(btnext);
36 cont.add(panel);
37 setVisible(true);
38 qaid=0;
39 readqa(qaid);
}
40 public void actionPerformed(ActionEvent
e){
if(btnext.getText().equals("Next")){
if(qaid<9){
map.put(qaid,getSelection());
qaid++;
readqa(qaid);
}
else {
map.put(qaid,getSelection());
btnext.setText("Show
answers");
}
}
else
if(btnext.getText().equals("Show answers"))
new
Report();
}
41 public void initializedata(){
//qpa stores pairs of
question and its possible answers
qpa=new String[10][5];
qpa[0][0]="How to
run Java program on the command prompt?";
qpa[0][1]="javac
JavaProgram";
qpa[0][2]="java
JavaProgram";
qpa[0][3]="javac
JavaProgram.java";
qpa[0][4]="No
one";
qpa[1][0]="What is
the use of the println method?";
qpa[1][1]="It is
used to print text on the screen.";
qpa[1][2]="It is
used to print text on the screen with the line break.";
qpa[1][3]="It is
used to read text from keyboard.";
qpa[1][4]="It is
used to read text from a file.";
qpa[2][0]="How to
read a character from the keyboard?";
qpa[2][1]="char
c=System.read()";
qpa[2][2]="char
c=System.in.read()";
qpa[2][3]="char
c=(char)System.read()";
qpa[2][4]="char
c=(char)System.in.read()";
qpa[3][0]="Which
one is a single-line comment?";
qpa[3][1]="/...";
qpa[3][2]="//...";
qpa[3][3]="/*...";
qpa[3][4]="/*...*/";
qpa[4][0]="How do
you declare an integer variable x?";
qpa[4][1]="int
x";
qpa[4][2]="x as
Integer";
qpa[4][3]="Int[]
x";
qpa[4][4]="No one
is correct.";
qpa[5][0]="How do
you convert a string of number to a number?";
qpa[5][1]="int
num=Integer.parseInt(str_num)";
qpa[5][2]="int
num=str_num.toInteger()";
qpa[5][3]="int
num=(int)str_num";
qpa[5][4]="int
num=(Integer)str_num";
qpa[6][0]="What is
the value of x? int x=3>>2";
qpa[6][1]="1";
qpa[6][2]="0";
qpa[6][3]="3";
qpa[6][4]="-3";
qpa[7][0]="How to
do exit a loop?";
qpa[7][1]="Using
exit";
qpa[7][2]="Using
break";
qpa[7][3]="Using
continue";
qpa[7][4]="Using
terminate";
qpa[8][0]="What is
the correct way to allocate one-dimensional array?";
qpa[8][1]="int[size]
arr=new int[]";
qpa[8][2]="int
arr[size]=new int[]";
qpa[8][3]="int[size]
arr=new int[size]";
qpa[8][4]="int[]
arr=new int[size]";
qpa[9][0]="What is
the correct way to allocate two-dimensional array?";
qpa[9][1]="int[size][]
arr=new int[][]";
qpa[9][2]="int
arr=new int[rows][cols]";
qpa[9][3]="int
arr[rows][]=new int[rows][cols]";
qpa[9][4]="int[][]
arr=new int[rows][cols]";
//qca stores pairs of
question and its correct answer
qca=new String[10][2];
qca[0][0]="How to
run Java program on the command prompt?";
qca[0][1]="java
JavaProgram";
qca[1][0]="What is
the use of the println method?";
qca[1][1]="It is
used to print text on the screen with the line break.";
qca[2][0]="How to
read a character from the keyboard?";
qca[2][1]="char
c=(char)System.in.read()";
qca[3][0]="Which
one is a single-line comment?";
qca[3][1]="//...";
qca[4][0]="How do
you declare an integer variable x?";
qca[4][1]="int
x";
qca[5][0]="How do
you convert a string of number to a number?";
qca[5][1]="int
num=Integer.parseInt(str_num)";
qca[6][0]="What is
the value of x? int x=3>>2";
qca[6][1]="0";
qca[7][0]="How to
do exit a loop?";
qca[7][1]="Using
break";
qca[8][0]="What is
the correct way to allocate one-dimensional array?";
qca[8][1]="int[]
arr=new int[size]";
qca[9][0]="What is
the correct way to allocate two-dimensional array?";
qca[9][1]="int[][]
arr=new int[rows][cols]";
//create a map object to
store pairs of question and selected answer
map=new
HashMap<Integer, String>();
}
42 public String getSelection(){
String
selectedChoice=null;
Enumeration<AbstractButton>
buttons=bg.getElements();
while(buttons.hasMoreElements())
{
JRadioButton
temp=(JRadioButton)buttons.nextElement();
if(temp.isSelected())
{
selectedChoice=temp.getText();
}
}
return(selectedChoice);
}
43 public void readqa(int qid){
lblmess.setText(" "+qpa[qid][0]);
choice1.setText(qpa[qid][1]);
choice2.setText(qpa[qid][2]);
choice3.setText(qpa[qid][3]);
choice4.setText(qpa[qid][4]);
choice1.setSelected(true);
}
44 public void reset(){
qaid=0;
map.clear();
readqa(qaid);
btnext.setText("Next");
}
45 public int calCorrectAnswer(){
int qnum=10;
int count=0;
for(int
qid=0;qid<qnum;qid++)
if(qca[qid][1].equals(map.get(qid)))
count++;
return count;
}
46 public class Report extends JFrame{
Report(){
setTitle("Answers");
setSize(850,550);
setBackground(Color.WHITE);
addWindowListener(new
WindowAdapter(){
public
void windowClosing(WindowEvent e){
dispose();
reset();
}
});
Draw d=new
Draw();
add(d);
setVisible(true);
}
47 class Draw extends Canvas{
public void
paint(Graphics g){
int
qnum=10;
int
x=10;
int
y=20;
for(int
i=0;i<qnum;i++){
//print
the 1st column
g.setFont(new
Font("Arial",Font.BOLD,12));
g.drawString(i+1+".
"+qca[i][0], x,y);
y+=30;
g.setFont(new
Font("Arial",Font.PLAIN,12));
g.drawString(" Correct answer:"+qca[i][1], x,y);
y+=30;
g.drawString(" Your answer:"+map.get(i), x,y);
y+=30;
//print
the 2nd column
if(y>400)
{y=20;
x=450;
}
}
//Show
number of correct answers
int
numc=calCorrectAnswer();
g.setColor(Color.BLUE);
g.setFont(new
Font("Arial",Font.BOLD,14));
g.drawString("Number
of correct answers:"+numc,300,500);
}
}
}
}
48 public
class QuizProgram{
public static void main(String
args[]){
new Quiz();
}
}
Code Explanation:
1 Initialize questions, possible answers, and correct answers.
2 Set the title of the program window (Quiz Program).
3 Let the program window close when the user clicks the close button.
4 Specify the width and height of the program window when it opens.
5 Specify the location of the program window when it opens.
6 Disable program window resizing.
7 Create a container object to act as the controls placeholder.
8 Set the layout of the container to null so that you can customize the locations of controls to place on it.
9 Set the background color of the container to the gray color.
10 Create the ButtonGroup object to hold the JRadioButton objects.
11-18 Create four JRadioButton objects and add them to the ButtonGroup bg. The radio buttons allows the user to choose the correct answer. The radio buttons are placed in the ButtonGroup to make sure that only one of the four answer choice can be selected.
19 Create a JLabel object lblmess to display the question.
20 Set the text color of the lblmess to the blue color.
21 Set the font name, font style, and font size of the lblshow label.
22 Create the JButton next object to enable next question.
23 Set the text color of the next button tot the green color.
24 Add action event tot button to enable button-click action.
25 Create the JPanel panel object to hold the controls (label, radio buttons, and button).
26 Set the background color of the panel to the light gray color.
27 Specify the location of the panel object.
28 Specify the width and height of panel object.
29 Set the layout of the panel to a grid layout with 6 rows and 2 columns.
30-35 Add all controls to the panel object.
36 Add the panel object to the container.
37 Make sure the program window is visible.
38 Initialize the question id.
39 Display the first question (id=0) and its answers choice to the user.
40 The actionPerformed method of the ActionListener interface is rewritten to handle the button click event.
41 Initialize the qpa and qca arrays. The qpa array stores pairs of question and its possible answers, and qca array stores pairs of question and its correct answers. The HashMap object also created. It will be uses to store the pairs of question and its selected answer.
42 The getSelection method returns the answer selected by the user from the answer choices list.
43 The readqa method is invoked to set the question to the lblmess, and answer choices text to the four radio buttons. The first radio button is selected by default.
44 The reset method reset the program back to its first load state.
45 The calCorrectAnswer method return the number of answers that are answered correctly.
46 The Report class extends JFrame. The report window is displayed when the user complete all questions and clicks the btnext button (label Show answers).
47 The Draw class extends Canvas. It is an inner class of the Report class. The Draw class is used to display the output to the user.
48 The QuizProgram class the main method to start the Quiz program.
