Question

Project 7-3 Guessing Game

import java.util.Scanner;

public class GuessNumberApp {
  
public static void main(String[] args) {
displayWelcomeMessage();

// create the Scanner object
Scanner sc = new Scanner(System.in);

String choice = "y";
while (choice.equalsIgnoreCase("y")) {
// generate the random number and invite user to guess it
int number = getRandomNumber();
displayPleaseGuessMessage();

// continue until the user guesses the number
int guessNumber = 0;
int counter = 1;
while (guessNumber != number) {
// get a valid int from user
guessNumber = getIntWithinRange(sc, "Enter number: ", 0, 101);

// display result of guess to user
if (guessNumber == number) {
displayCorrectGuessMessage(counter);
} else {
displayGuessAgainMessage(number, guessNumber);
}
counter++;
}

// see if the user wants to continue
choice = getChoiceString(sc, "Try again? (y/n): ", "y", "n");
System.out.println();
}
System.out.println("Bye - Come back soon!");
System.out.println();
}

private static void displayWelcomeMessage() {
System.out.println("Welcome to the Guess the Number Game");
System.out.println("++++++++++++++++++++++++++++++++++++");
System.out.println();
}
  
private static int getRandomNumber() {
return (int) (Math.random() * 100) + 1;
}
  
private static void displayPleaseGuessMessage() {
System.out.println("I'm thinking of a number from 1 to 100.");
System.out.println("Try to guess it.");
System.out.println();
}
  
private static void displayCorrectGuessMessage(int counter) {
System.out.println("You got it in " + counter + " tries.");
if (counter <= 3) {
System.out.println("Great work! You are a mathematical wizard.\n");
} else if (counter > 3 && counter <= 7) {
System.out.println("Not too bad! You've got some potential.\n");
} else {
System.out.println("What took you so long? Maybe you should take some lessons.\n");
}
}
  
private static void displayGuessAgainMessage(int number, int guessNumber) {
int difference = guessNumber - number;
if (guessNumber > number) {
if (difference > 10) {
System.out.println("Way too high! Guess again.\n");
} else {
System.out.println("Too high! Guess again.\n");
}
} else {
if (difference < -10) {
System.out.println("Way to low! Guess again.\n");
} else {
System.out.println("Too low! Guess again.\n");
}
}
}

private static int getInt(Scanner sc, String prompt) {
int i = 0;
boolean isValid = false;
while (!isValid) {
System.out.print(prompt);
if (sc.hasNextInt()) {
i = sc.nextInt();
isValid = true;
} else {
System.out.println("Error! Invalid integer value. Try again.");
}
sc.nextLine(); // discard any other data entered on the line
}
return i;
}

private static int getIntWithinRange(Scanner sc, String prompt,
int min, int max) {
int i = 0;
boolean isValid = false;
while (!isValid) {
i = getInt(sc, prompt);
if (i <= min) {
System.out.println("Error! Number must be greater than " + min);
} else if (i >= max) {
System.out.println("Error! Number must be less than " + max);
} else {
isValid = true;
}
}
return i;
}

private static String getRequiredString(Scanner sc, String prompt) {
String s = "";
boolean isValid = false;
while (!isValid) {
System.out.print(prompt);
s = sc.nextLine();
if (s.equals("")) {
System.out.println("Error! This entry is required. Try again.");
} else {
isValid = true;
}
}
return s;
}

private static String getChoiceString(Scanner sc, String prompt,
String s1, String s2) {
String s = "";
boolean isValid = false;
while (!isValid) {
s = getRequiredString(sc, prompt);
if (!s.equalsIgnoreCase(s1) && !s.equalsIgnoreCase(s2)) {
System.out.println("Error! Entry must be '" + s1 + "' or '" + s2 + "'. Try again.");
} else {
isValid = true;
}
}
return s;
}
}

Criteria:

Console class-Create a class named Console

Move retrieve methods to Console- Move all the methods that retrieve user input to Console

Move validate methods to Console- Move all the methods that validate user input to Console

This criterion is linked to a Learning OutcomeConsole static methods-Console class methods remain static

Game class- Create a class named Game

This criterion is linked to a Learning OutcomeMove display methods to Game-Move all the methods that display messages to the Game class

Move guess methods to Game- Move all the methods that handle user guesses to the Game class

Game instance methods- Adjust Game methods so they aren't static

Game instance variables-Use instance variables of the Game class to keep track of numbers, guesses, and so on

Answer 1

Following is the answer:

All the methods that are getting the input from the console are moved to this class

Console.java

import java.util.Scanner;

public class Console {

    Console(){}

    public static int getInt(Scanner sc, String prompt) {
        int i = 0;
        boolean isValid = false;
        while (!isValid) {
            System.out.print(prompt);
            if (sc.hasNextInt()) {
                i = sc.nextInt();
                isValid = true;
            } else {
                System.out.println("Error! Invalid integer value. Try again.");
            }
            sc.nextLine(); // discard any other data entered on the line
        }
        return i;
    }

    public static int getIntWithinRange(Scanner sc, String prompt,
                          int min, int max) {
        int i = 0;
        boolean isValid = false;
        while (!isValid) {
            i = getInt(sc, prompt);
            if (i <= min) {
                System.out.println("Error! Number must be greater than " + min);
            } else if (i >= max) {
                System.out.println("Error! Number must be less than " + max);
            } else {
                isValid = true;
            }
        }
        return i;
    }

    public static String getRequiredString(Scanner sc, String prompt) {
        String s = "";
        boolean isValid = false;
        while (!isValid) {
            System.out.print(prompt);
            s = sc.nextLine();
            if (s.equals("")) {
                System.out.println("Error! This entry is required. Try again.");
            } else {
                isValid = true;
            }
        }
        return s;
    }

    public static String getChoiceString(Scanner sc, String prompt,
                                  String s1, String s2) {
        String s = "";
        boolean isValid = false;
        while (!isValid) {
            s = getRequiredString(sc, prompt);
            if (!s.equalsIgnoreCase(s1) && !s.equalsIgnoreCase(s2)) {
                System.out.println("Error! Entry must be '" + s1 + "' or '" + s2 + "'. Try again.");
            } else {
                isValid = true;
            }
        }
        return s;
    }
}

All the methods are that are used to display the messages and helper methods are moved to this class and all methods are not static methods.

Game.java

public class Game {

    Game(){}

    public void displayWelcomeMessage() {
        System.out.println("Welcome to the Guess the Number Game");
        System.out.println("++++++++++++++++++++++++++++++++++++");
        System.out.println();
    }

    public int getRandomNumber() {
        return (int) (Math.random() * 100) + 1;
    }

    public void displayPleaseGuessMessage() {
        System.out.println("I'm thinking of a number from 1 to 100.");
        System.out.println("Try to guess it.");
        System.out.println();
    }

    public void displayCorrectGuessMessage(int counter) {
        System.out.println("You got it in " + counter + " tries.");
        if (counter <= 3) {
            System.out.println("Great work! You are a mathematical wizard.\n");
        } else if (counter > 3 && counter <= 7) {
            System.out.println("Not too bad! You've got some potential.\n");
        } else {
            System.out.println("What took you so long? Maybe you should take some lessons.\n");
        }
    }

    public void displayGuessAgainMessage(int number, int guessNumber) {
        int difference = guessNumber - number;
        if (guessNumber > number) {
            if (difference > 10) {
                System.out.println("Way too high! Guess again.\n");
            } else {
                System.out.println("Too high! Guess again.\n");
            }
        } else {
            if (difference < -10) {
                System.out.println("Way to low! Guess again.\n");
            } else {
                System.out.println("Too low! Guess again.\n");
            }
        }
    }


}

GuessNumberApp.java

import java.util.Scanner;

public class GuessNumberApp {

    public static void main(String[] args) {

        Game game = new Game();

        game.displayWelcomeMessage();

        // create the Scanner object
        Scanner sc = new Scanner(System.in);

        String choice = "y";
        while (choice.equalsIgnoreCase("y")) {
            // generate the random number and invite user to guess it
            int number = game.getRandomNumber();
            game.displayPleaseGuessMessage();

            // continue until the user guesses the number
            int guessNumber = 0;
            int counter = 1;
            while (guessNumber != number) {
                // get a valid int from user
                guessNumber = Console.getIntWithinRange(sc, "Enter number: ", 0, 101);

                // display result of guess to user
                if (guessNumber == number) {
                    game.displayCorrectGuessMessage(counter);
                } else {
                    game.displayGuessAgainMessage(number, guessNumber);
                }
                counter++;
            }

            // see if the user wants to continue
            choice = Console.getChoiceString(sc, "Try again? (y/n): ", "y", "n");
            System.out.println();
        }
        System.out.println("Bye - Come back soon!");
        System.out.println();
    }
}

Output: