PROJECT: Quiz Game. Java Projects: Quiz Game STEP 1 CREATE A CLASS

Transcription

1 You will need to have covered all of the Java basics tutorials before going any further, please make sure you have completed them all. If you have any questions or get stuck ask a mentor or the person next to you for help. PROJECT: Quiz Game In this project you will learn how to make a quiz game using Java and the JOptionPane tools. You will also need to use methods and global variables to keep track of the score. STEP 1 CREATE A CLASS We will start by creating a class called MyQuiz with a main method. Add a second method called checkanswer(); which will be used to check if the answer given by the user is correct. The method checkanswer(); will take 3 parameters, a String for the question, a String for the answer and an int for the amount of points that question is worth. 1 P a g e

2 STEP 2 KEEPING A SCORE In order for this game to be successful we have to make sure we have a way to keep our score tracked by the use of a global variable. Global variables are defined outside our methods. Now the score variable can be accessed throughout all our methods inside our class. package myfirstjavaprojects; public class MyQuiz { static int score = 0; public static void main(string[] args) { public static int checkanswer(string question, String answer, int points) { return points; If you have any questions or are stuck please ask a mentor or a person next to you for help. 2 P a g e

3 STEP 3 ASKING QUESTIONS The first thing we got to implement is the way the program will ask questions. We will use the JOptionPane.showInputDialog(); function to ask for an answer to our questions. package myfirstjavaprojects; import javax.swing.joptionpane; public class MyQuiz { static int score = 0; public static void main(string[] args) { score += checkanswer("what colour is the Sun?", "Yellow", 10); public static int checkanswer(string question, String answer, int points) { String input = JOptionPane.showInputDialog(null, question, "Question worth " + points + " points.", JOptionPane.OK_CANCEL_OPTION); return points; Your code now asks questions! But wait, how can we check the answers? 3 P a g e

4 STEP 4 CHECKING ANSWERS We have figured out most of our code for generating the quiz questions, however how can we check for correct answers? We will use an if statement to check if the input variable is the same as answer, if so then award the points, else make the points be 0. We will also change both of the String values to lowercase so that we can match for different capitalisation of the answers. In the code above you can see that the use of the tolowercase(); method was used. This method will convert any capital letters into lower case. We must do this because Java is a case-sensitive language which means it would actually say ORANGE and Orange is NOT the same. The.equals() method inside the if statement is used because String values are not the same internally. The function makes sure they are typed the same way, but not if they hold the same values in memory. If they are not equal (else) then points will become 0. Do not forget! If you get stuck ask a mentor or the person next to you for help. 4 P a g e

5 STEP 5 SHOWING YOUR SCORE You can now add as many questions as you want using the score += checkanswer("what colour is the Sun?", "Yellow", 10); in your main method. Another thing to consider is adding a total score at the end of the quiz, like this: A good thing to have is to show the users whenever they get a question wrong or right. 5 P a g e

6 package myfirstjavaprojects; import javax.swing.joptionpane; public class MyQuiz { static int score = 0; public static void main(string[] args) { score += checkanswer("what colour is the Sun?", "Yellow", 10); score += checkanswer("what colour is the sea?", "Blue", 10); score += checkanswer("what is Java?", "A Programming Language", 10); JOptionPane.showMessageDialog(null, "Your total score is... " + score +"!\nwell Done!"); public static int checkanswer(string question, String answer, int points) { String input = JOptionPane.showInputDialog(null, question, "Question worth " + points + " points.", JOptionPane.QUESTION_MESSAGE); input = input.tolowercase(); answer = answer.tolowercase(); if (input.equals(answer)) { JOptionPane.showMessageDialog(null, "Correct! You earned " + points + " points."); else { points = 0; JOptionPane.showMessageDialog(null, "Wrong! You get " + points + " points."); return points; You are finished! Well done for completing this project. You can now create any quiz you like and ask your friends to complete it. 6 P a g e