Guessing Game Assignment

• Analyze a problem to determine requirements
• Write a Java class to meet specified requirements
• Test and debug an application
• Compile a multi-file Java application
• Use object-oriented programming techniques when creating a class
• Follow Java coding style guidelines

You have to create a class that can support the game of having the user guess a number within a range and telling the user whether their guess is high, low, or correct. Most of the game logic is already given to you in a file named PlayGuessingGame.java. Some utility routines for input are provided in a file named Keyboard.java. You have to create a class named HiLoGame that provides the missing functionality. You have to determine the requirements for HiLoGame by examining the code in PlayGuessingGame.java.

• PlayGuessingGame.java
• Keyboard.java

1 /* 2 PlayGuessingGame.java 3 Dave Klick 4 CIS 260 5 2015-01-13 6 7 This program uses the HiLoGame class to play a number 8 guessing game. It is provided as a driver to be used 9 once the HiLoGame class has been implemented. 10 11 Note: This class depends upon the presence of Keyboard.java 12 (or Keyboard.class) in the same directory. Keyboard.java is 13 provided on the course web site. 14 */ 15 16 public class PlayGuessingGame { 17 public static void main(String[] args) { 18 int low = 100; 19 int high = 1; 20 int guess = 0; 21 char again = 'Y'; 22 String result = ""; 23 int status; 24 Keyboard kbd = new Keyboard(); 25 26 while (again == 'Y') { 27 HiLoGame game = new HiLoGame(high, low); 28 status = HiLoGame.LOW; 29 System.out.printf("Guess the secret number between %d and %d\n", game.getLow(), game.getHigh()); 30 while (status != HiLoGame.CORRECT) { 31 guess = kbd.getInt("Your guess: ", game.getLow(), game.getHigh()); 32 status = game.checkGuess(guess); 33 switch (status) { 34 case HiLoGame.LOW: result = "low"; break; 35 case HiLoGame.HIGH: result = "high"; break; 36 case HiLoGame.CORRECT: result = "correct"; break; 37 default: result = "undefined"; break; 38 } 39 System.out.printf("Your guess #%d was %s\n", game.getGuesses(), result); 40 } 41 System.out.println("Congratulations!"); 42 System.out.printf("You got the right number in %d guesses.\n\n", game.getGuesses()); 43 again = Character.toUpperCase(kbd.getChar("Play again (Y/N)? ", "YyNn")); 44 } 45 46 System.out.printf("\n%d %s played.\n", HiLoGame.getGames(), 47 HiLoGame.getGames() == 1 ? "game was" : "games were"); 48 } 49 }

• You should assume all fields in HiLoGame are private unless otherwise indicated.
• All fields (class-level variables) that make sense to be constant ("final") should be declared that way.
• Lines 18-19 indicate the HiLoGame class must be alert for the low and high values being out of order and swap them if needed
• Line 27 requires a constructor which accepts two integers (high and low). Since no code after this point requests a new number and the guessing (using checkGuess) starts in a few lines, we know that the constructor must be choosing a random number within the given range and storing it for use in checking guesses.
• Lines 28, 34-36 show that there must be constants in the class for LOW, HIGH, and CORRECT. These must be integer constants (since they are being stored in "status", which is an int. They must also be static fields since they are being accessed using the class name and not an object reference. They should have public access since the code is accessing them directly from another class.
• Line 29 requires accessor methods named getLow and getHigh which return the values sent to the constructor (which were swapped if needed). This means that those values should have been stored by the constructor.
• Line 32 requires a checkGuess method which returns HiLoGame.LOW, HiLoGame.HIGH, or HiLoGame.CORRECT. Since the HiLoGame constructor presumably generated a random number and saved it, and this method has been sent the user guess, it should be fairly straight-forward to figure out the logic needed to return one of the constant values.
• Lines 39, 42 require a getGuesses method which tells us how many times checkGuess has been called. This means there must be a field in HiLoGame to keep track of the number of guesses and that checkGuess must increment that field. Since guesses are per game (which is equivalent to being per HiLoGame object in this case), this field must be an instance variable.
• Lines 46, 47 require a getGames method which tells us how many HiLoGames have been played. A look at the code reveals that a new HiLoGame object/instance is created for each game. A variable/field tied to the class rather than to an instance/object must keep track of the number of HiLoGame objects that have been created. Every time the constructor is called it should increment this variable. The getGames method returns this value. This method is also tied to the class rather than to an object since it is called using the class name.

Guess the secret number between 1 and 100 Your guess: 50 Your guess #1 was high Your guess: 25 Your guess #2 was high Your guess: 12 Your guess #3 was high Your guess: 6 Your guess #4 was low Your guess: 9 Your guess #5 was low Your guess: 10 Your guess #6 was correct Congratulations! You got the right number in 6 guesses. Play again (Y/N)? 5 Error: Character entered is not a valid response. Play again (Y/N)? y Guess the secret number between 1 and 100 Your guess: 900 Error: Above maximum value of 100 Your guess: -9 Error: Below minimum value of 1 Your guess: 50 Your guess #1 was high Your guess: 25 Your guess #2 was low Your guess: 37 Your guess #3 was high Your guess: 31 Your guess #4 was high Your guess: 28 Your guess #5 was low Your guess: 29 Your guess #6 was correct Congratulations! You got the right number in 6 guesses. Play again (Y/N)? n 2 games were played.

• 5 points for following coding conventions and having documentation comments
• 8 points for having working accessor methods with the appropriate access modifiers
• 12 points for having the constructor working properly
• 10 points for having methods other than the constructor and accessor methods working properly and having the appropriate access permissions
• 5 points for having the required working constants with appropriate modifiers
• 8 points for having fields as required with the appropriate modifiers
• 2 points for using the "final" modifier for all method parameters and where appropriate for fields (class-level variables)