Outcomes: Using the decision constructs in a Java Application Using the looping

Question

Outcomes:

Using the decision constructs in a Java Application

Using the looping constructs in a Java Application

Uses an array of objects in a Java Application

Use more than one class and multiple objects in in a Java Application

Preparatory Readings

Absolute Java Chapters 1 - 6

Background Information:

For this assignment, you are going to build a program that plays a simple trivia game.. Your program will ask the user a question, obtain the answers and evaluate the answer.

The Unified Modeling Language (UML) provides a useful notation for designing and developing object-oriented software systems. One of the basic components of the UML is a class diagram, which are used to depict the attributes and behaviors of a class. A basic class diagram (as shown in the figure below) has three components. The first is the class name. The second component includes the class's attributes or fields. Each attribute is followed by a colon (:) and its data type. The third component includes the class's behaviors or methods. If the method takes parameters, their types are included in parentheses. Each behavior is also followed by a colon (:) and its return type. If the return value of a method is void, the return type can be omitted. For more information on the UML, refer to http://www.uml.org/.

Project Requirements:

Develop a simple TriviaGame program. We will have two classes, a TriviaGame class and a Question class. The TriviaGame class will contain several Question objects stored in an array and will have several operations. We will also have a tester class to test the PlayTriviaGame class.

Specific Requirements for the Question class:

Constant - INVALIDVALUE = -1. (see details below)

Instance variables

String question - The trivia question

String answer - The answer to the question

int value

the value of the question.

The value will be between 1 - 5 (inclusive) based on difficulty , 1 is easy, 5 is difficult.

Your program must ensure that the value is in the range of 1 -5, if not print out an error message and set the value to the constant INVALIDVALUE.

Default constructor that sets all instance variables to default values.

A parameterizes constructor that takes in parameters to set the class's instance variables . Ensure value is check for validity (hint call the mutator method for value and do your error handling there)

Accessor and mutator methods for all the instance variables (see UML Class diagram above)

toString() returns a nicely formatted with one attribute on each line using the ' ' escape character (see sample output below for an example).

The UML class diagram for the Question class looks like this:

Specific Requirements for theTriviaGame class:Instance Variables

Question[] gameQuestions - size of 10.

int score - the current score of the user playing the game

int numberOfQuestion - the number of question used in the current game, (partially filled array value) it can not be greater than the size of the array of question. (10).

int currentQuestion - the index of the current question being asked.

Parameterized constructor

Parameter - a FileInputStream object (chpt 2). The FileInputStreamObject is connected to a file that contains the 10 questions, their respective answers and values.

Reads the file one line at a time, creates Question object from each line and stores the Question object in the array of questions.

See the sample file posted on elearning. The file structure is one line for the question, one line for the answer and one line for the question value.

sets currentQuestion instance variable to zero.

Methods

Accessor methods for score, numberOfQuestions and currentQuestion instance variable. no mutator method needed

play method -Starts the game.

resets the score and currentQuestion instance variable to zero.

parameter - int numQuestion representing the number of question the player want to answer for this game. (Maximum of 10)

nextQuestion method

Uses the currentQuestion instance variable to access the gameQuestion array.

Returns the a String representing the next question..

evaluateAnswer(String answer)

Compares the parameter answer with the currentQuestion answer.

Returns true if correct, false if incorrect.

Increment the currentQuestion variable.

toString method - prints a nicely formated string that lists all the questions in the array, their respective answers and score value.

The UML class diagram for the TriviaGame class looks like this:

Build a PlayTrivaGame class to play a game of trivia.

Create a FileInputStreamObject - NOTE for ease of grading, call the file used to create this object questions.dat. You can just use the sample file provide if you like.

Create a TriviaGame Object that passes a FileInputStreamObject that connect to the file with the questions, answers and scores.

Prompt the user to input how many question they would like to answer, up to a maximum of 10.

Calls the play method passing the number of question from item 2.

Loops through the follow until the number of question from item 2 are asked and answered.

Calls nextQuestion and displays the next question

Prompts for the answer

Calls evalutateAnswer method and prints message depend on evaluteAnswer results such as answer is correct, or answer is incorrect.

Once current game is complete calls getScore and displays the current players score.

Ask the user if they wish to try again and if so go back to step 3,(calling the play method).

If the user wishes to exit, call the Trivia game toString method and exit the program.

Submission Requirements:

Your project must be submitted using our standard submission procedures.

You should turn in the following files for this assignment:

Question.java

Trivia.java

PlayTriviaGame.java

Remember to include javadoc for all the classes. See the Programming Project Comments Template and Java Commented Sample Code under Chapter 5 on elearning

Question question String
answer: String
value: int Question()
Question(String, String, int)getQuestion(): String
getAnswer(): String
getValue(): int
setQuestion(String)
setAnswer(String)
setValue(int)
toString: String

Explanation / Answer

Question.java

/**
*Question class
*/
public class Question {
  
   private String question;
   private String answer;
   private int value;
   private final static int INVALIDVALUE = -1;
  
   public Question() {
   }
   public Question(String question, String answer, int value) {
       super();
       this.question = question;
       this.answer = answer;
       setValue(value);
   }
   public String getQuestion() {
       return question;
   }
   public void setQuestion(String question) {
       this.question = question;
   }
   public String getAnswer() {
       return answer;
   }
   public void setAnswer(String answer) {
       this.answer = answer;
   }
   public int getValue() {
       return value;
   }
   public void setValue(int value) {
       if (value >= 1 && value <= 5)
           this.value = value;
       else
           this.value = this.INVALIDVALUE;
   }
   @Override
   public String toString() {
       return " Question = " + question + " Answer = " + answer
               + " Value = " + value;
   }  

}

TriviaGame.java

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

/**
*Trivia Game class
*/
public class TriviaGame {
  
   private Question[] gameQuestions = new Question[10];
   private int score;
   private int numberOfQuestion;
   private int currentQuestion;
  
   public TriviaGame(FileInputStream input) {
       this.currentQuestion = 0;
       BufferedReader reader = new BufferedReader(new InputStreamReader(input));
       while (currentQuestion < 10) {
           gameQuestions[currentQuestion] = new Question();
           try {
               gameQuestions[currentQuestion].setQuestion(reader.readLine());
               gameQuestions[currentQuestion].setAnswer(reader.readLine());
               gameQuestions[currentQuestion].setValue(Integer.parseInt(reader.readLine()));
           } catch (IOException e) {
               e.printStackTrace();
           }
           currentQuestion++;
       }
   }

   public int getScore() {
       return score;
   }

   public int getNumberOfQuestion() {
       return numberOfQuestion;
   }

   public int getCurrentQuestion() {
       return currentQuestion;
   }
  
   public void play(int numQuestion) {
       this.score = 0;
       this.currentQuestion = 0;
   }
  
   public String nextQuestion() {
       return gameQuestions[currentQuestion].getQuestion();
   }
  
   public boolean evaluateAnswer(String answer) {
       boolean check = answer.equals(gameQuestions[currentQuestion++].getAnswer());
       if (check)
           score++;
       return check;
   }

   @Override
   public String toString() {
       return "GameQuestions: " + Arrays.toString(gameQuestions);
   }

}

PlayTriviaGame.java

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Scanner;

/**
*PlayTriviaGame class
*/
public class PlayTriviaGame {
  
   public static void main(String[] args) {
       try {
           FileInputStream fis = new FileInputStream("question.dat");
           TriviaGame game = new TriviaGame(fis);
           Scanner scanner = new Scanner(System.in);
           int choice;
           do {
               System.out.println("Press 1 to play the game");
               System.out.println("Press 2 to exit");
               choice = scanner.nextInt();
               if (choice == 1) {
                   System.out.println("Enter number of questions you would like to answer, the maximum being 10");
                   int numQuestion = scanner.nextInt();
                   String answer = null;
                   game.play(numQuestion);
                   for (int i = 0; i < numQuestion; i++) {
                       System.out.println("Question is: " + game.nextQuestion());
                       System.out.println("Please enter your answer");
                       answer = scanner.next();
                       if (game.evaluateAnswer(answer)) {
                           System.out.println("Correct answer");
                       }
                       else {
                           System.out.println("Incorrect answer");
                       }
                   }
                   System.out.println("Game is complete. Your score is: " + game.getScore());
               }
           } while (choice != 2);
           System.out.println(game);
       } catch (FileNotFoundException e) {
           e.printStackTrace();
       }
      
   }

}

Related Questions

Navigate

• Browse (All)
• Browse O
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.