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Java Java Objects (Retired) Delivering the MVP Refactoring

Posted by ISAIAH S
ISAIAH S
1,409 Points

./Prompter.java:24: error: cannot find symbol isHit = mGame.applyGuess...

Error:

./Prompter.java:24: error: cannot find symbol                                        
      isHit = mGame.applyGuess(guessAsString);                                       
                               ^                                                     
  symbol:   variable guessAsString                                                   
  location: class Prompter                                                           
1 error

Code:

Hangman.java:

public class Hangman {

    public static void main(String[] args) {
        // Enter amazing code here:
      Game game = new Game("treehouse");
      Prompter prompter = new Prompter(game);
      prompter.play();
    }

}

Game.java:

public class Game {
  public static final int MAX_MISSES = 7;
  private String mAnswer;
  private String mHits;
  private String mMisses;

  public Game(String answer) {
    mAnswer = answer;
    mHits = "";
    mMisses = "";
  }

  private char validateGuess(char letter) {
    if (! Character.isLetter(letter)) {
      throw new IllegalArgumentException("A letter is required");
    }
    letter = Character.toLowerCase(letter);
    if (mMisses.indexOf(letter) >= 0 || mHits.indexOf(letter) >= 0) {
      throw new IllegalArgumentException(letter + " has already been guessed");
    }
        return letter;
  }

  public boolean applyGuess(String letters) {
    if (letters.length() == 0) {
      throw new IllegalArgumentException("No letter found.");
    }
    return applyGuess(letters.charAt(0));
  }

  public boolean applyGuess(char letter) {
    letter = validateGuess(letter);
    boolean isHit = mAnswer.indexOf(letter) >= 0;
    if (isHit) {
      mHits += letter;
    } else {
      mMisses += letter;
    }
    return isHit;
  }

  public String getCurrentProgress() {
    String progress = "";
    for (char letter: mAnswer.toCharArray()) {
      char display = '-';
      if (mHits.indexOf(letter) >= 0) {
        display = letter;
      }
      progress += display;
    }
    return progress;
  }
  public int getRemainingTries() {
  return MAX_MISSES - mMisses.length(); 
  }

  }

Prompter.java:

import java.io.Console;

public class Prompter {
  private Game mGame;

  public Prompter(Game game) {
    mGame = game;
  }
  public void play() {
    while(mGame.getRemainingTries() > 0) {
      displayProgress();
      promptForGuess();
    }
  }

  public boolean promptForGuess() {
    Console console = System.console();
    boolean isHit = false;
    boolean isValidGuess = false;
    while (! isValidGuess) {
    String guessAsString = console.readLine("Enter a letter:  ");
    }
    try {
      isHit = mGame.applyGuess(guessAsString);
      isValidGuess = true;

    } catch (IllegalArgumentException iae) {
      console.printf("%s. Please try again.", iae.getMessage());
    }
    return isHit;
  }

  public void displayProgress() {
    System.out.printf("You have %d tries left to solve:  %s\n",
                      mGame.getRemainingTries(),
                      mGame.getCurrentProgress());
  }

}

2 Answers

Rob Bridges
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points
Rob Bridges
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points

I spent about 20 minutes going through your game class and comparing it to mine, even coping yours in and compiling it and the class complied, so that is very odd. However I have copied my game class below, try to insert this and see if it works, very odd.

public class Game {
  public static final int MAX_MISSES = 7;
  private String mAnswer;
  private String mHits;
  private String mMisses;

  public Game(String answer) {
    mAnswer = answer;
    mHits = "";
    mMisses = "";

  }
  public String getAnswer() {
    return mAnswer;
  }

  private char validateGuess(char letter) {
    if(! Character.isLetter(letter)) {
      throw new IllegalArgumentException("A letter is required");
    }
    letter = Character.toLowerCase(letter);
    if (mMisses.indexOf(letter) >= 0 || mHits.indexOf(letter) >= 0) {
      throw new IllegalArgumentException(letter + "has already been guessed");
    }
    return letter;
  }

  public boolean applyGuess (String letters) {
    if (letters.length() == 0) {
      throw new IllegalArgumentException("No letter found");
    }
    return applyGuess(letters.charAt(0));
  }



  public boolean applyGuess(char letter) {
    letter = validateGuess(letter);
    boolean isHit = mAnswer.indexOf(letter) >= 0;
     if (isHit) {
       mHits += letter;
     } else {
       mMisses += letter;
     }
    return isHit;
  }

  public String getCurrentProgress() {
    String progress = "";
    for (char letter : mAnswer.toCharArray()) {
      char display = '-';
      if (mHits.indexOf(letter) >= 0) {
        display = letter;
      }
      progress += display;
    }
    return progress;
}


public int getRemainingTries() {
  return MAX_MISSES - mMisses.length();
}

}

Let me know if this clears up the error, but I couldn't find it in your code.

ISAIAH S
ISAIAH S
1,409 Points

It worked!!! :-)

Rob Bridges
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points
Rob Bridges
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points

Good news!

Happy to hear it, it must have been something so minor, or just a glitch in workspaces, because when I tried what you initally copied over to me it compiled since all your edits were to the prompter class, at least it worked out!

Let me know if anything else comes up.

mannyaharon
mannyaharon
873 Points

Hi rob! I seem to be having the same issue and when I compile I get the same error. What's weird is that I can still run the program but all that will happen is I will be prompted for a letter and nothing will happen, it just loops indefinitely until I hit control 'c'. I even copied your code after going through my code for an hour because I wanted to see what would happen, and I still get the same error. Not sure what to do from here :( -emanuel

mannyaharon
mannyaharon
873 Points

Thanks for your Rob, Here is my code...

Hangman Class: 

public class Hangman {

    public static void main(String[] args) {
        // Enter amazing code here:
      Game game = new Game("treehouse");
      Prompter prompter = new Prompter(game);
      prompter.play();
    }

}

Game class:

public class Game {
  public static final int MAX_MISSES = 7;
  private String mAnswer;
  private String mHits;
  private String mMisses;

  public Game(String answer) {
    mAnswer = answer;
    mHits = "";
    mMisses = "";

  }
  public String getAnswer() {
    return mAnswer;
  }

  private char validateGuess(char letter) {
    if(! Character.isLetter(letter)) {
      throw new IllegalArgumentException("A letter is required");
    }
    letter = Character.toLowerCase(letter);
    if (mMisses.indexOf(letter) >= 0 || mHits.indexOf(letter) >= 0) {
      throw new IllegalArgumentException(letter + "has already been guessed");
    }
    return letter;
  }

  public boolean applyGuess (String letters) {
    if (letters.length() == 0) {
      throw new IllegalArgumentException("No letter found");
    }
    return applyGuess(letters.charAt(0));
  }



  public boolean applyGuess(char letter) {
    letter = validateGuess(letter);
    boolean isHit = mAnswer.indexOf(letter) >= 0;
     if (isHit) {
       mHits += letter;
     } else {
       mMisses += letter;
     }
    return isHit;
  }

  public String getCurrentProgress() {
    String progress = "";
    for (char letter : mAnswer.toCharArray()) {
      char display = '-';
      if (mHits.indexOf(letter) >= 0) {
        display = letter;
      }
      progress += display;
    }
    return progress;
}


public int getRemainingTries() {
  return MAX_MISSES - mMisses.length();
}

}

Prompter class:

import java.io.Console;

public class Prompter {
  private Game mGame;

  public Prompter(Game game) {
    mGame = game;
  }
  public void play() {
    while(mGame.getRemainingTries() > 0) {
      displayProgress();
      promptForGuess();
    }
  }

  public boolean promptForGuess() {
    Console console = System.console();
    boolean isHit = false;
    boolean isValidGuess = false;
    while (! isValidGuess) {
    String guessAsString = console.readLine("Enter a letter:  ");
    }
    try {
      isHit = mGame.applyGuess(guessAsString);
      isValidGuess = true;

    } catch (IllegalArgumentException iae) {
      console.printf("%s. Please try again.", iae.getMessage());
    }
    return isHit;
  }

  public void displayProgress() {
    System.out.printf("You have %d tries left to solve:  %s\n",
                      mGame.getRemainingTries(),
                      mGame.getCurrentProgress());
  }

}

The error I receive still is:

treehouse:~/workspace$ javac Hangman.java                                           
./Prompter.java:24: error: cannot find symbol                                       
      isHit = mGame.applyGuess(guessAsString);                                      
                               ^                                                    
  symbol:   variable guessAsString                                                  
  location: class Prompter                                                          
1 error

Thank you for all your help in advance!

Warm Regards, Emanuel

Rob Bridges
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points
Rob Bridges
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points

Okay, I looked over your code with a fine tooth comb, it looks like you had it right the first time with your line of 

isHit = mGame.applyGuess(guessAsString);

Sorry I didn't see that you had correctly declared the variable above it. Looking over it I see there is an closing curly brace above your first try block as GuessAsString,

I think this might also be the problem as well.

You want to keep your while block open during this until it is still a valid guess, sorry to run you in circles on this I gave it a better look,

Let's try this. 

public static boolean promptForGuess() {
    Console console = System.console();
    boolean isHit = false;
    boolean isValidGuess = false;
    while (! isValidGuess) {
      String guessAsString = console.readLine("Enter a letter: ");

      try {
        isHit = mGame.applyGuess(guessAsString);
        isValidGuess =true;
      } catch (IllegalArgumentException iae) {
        console.printf("%s. Please try again.\n", iae.getMessage());
      }
  }
    return isHit;
}

Use that as your for promptForGuess, it is much like your's except it is removing the extra curly brace.

Let me know if this helps, if not I'll be back in touch till we get this worked out.

ISAIAH S
ISAIAH S
1,409 Points

I changed

 try { isHit = mGame.applyGuess(guessAsString); isValidGuess = true;

to

 try { isHit = mGame.applyGuess(String guessAsString); isValidGuess = true;

but I am getting the following errors:

./Prompter.java:24: error: ')' expected                                              
      isHit = mGame.applyGuess(String guessAsString);                                
                                     ^                                               
./Prompter.java:24: error: illegal start of expression                               
      isHit = mGame.applyGuess(String guessAsString);                                
                                                   ^                                 
./Prompter.java:24: error: cannot find symbol                                        
      isHit = mGame.applyGuess(String guessAsString);                                
                               ^                                                     
  symbol:   variable String                                                          
  location: class Prompter                                                           
3 errors
ISAIAH S
ISAIAH S
1,409 Points

No.

ISAIAH S
ISAIAH S
1,409 Points

I changed

 public static boolean promptForGuess() {
    Console console = System.console();
    boolean isHit = false;
    boolean isValidGuess = false;
    while (! isValidGuess) {
      String guessAsString = console.readLine("Enter a letter: ");

      try {
        isHit = mGame.applyGuess(guessAsString);
        isValidGuess = true;
      } catch (IllegalArgumentException iae) {
        console.printf("%s. Please try again.\n", iae.getMessage());
      }
  }
    return isHit;
}

to this 

public static boolean promptForGuess() {
    Console console = System.console();
    boolean isHit = false;
    boolean isValidGuess = false;
    while (! isValidGuess) {
      String guessAsString = console.readLine("Enter a letter: ");

      try {
        isHit = mGame.applyGuess(guessAsString);
        isValidGuess = true;
      } catch (IllegalArgumentException iae) {
        console.printf("%s. Please try again.\n", iae.getMessage());
      }
  }
    return isHit;
}

but I am getting the following error:

Prompter.java:24: error: non-static variable mGame cannot be referenced from 
a static context                                                             
        isHit = mGame.applyGuess(guessAsString);                             
                ^                                                            
1 error
Rob Bridges
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points
Rob Bridges
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points

Hello, that is actually good news. We got past one error and onto the next.

This one is a an easy fix, in your Prompter Java class towards the top where you are defining the mGame Variable, it is the towards the very top, it looks like.

private  Game mGame;

Give it the keyword "static" which allows it to be referenced inside your loops

So it should look something like

private static Game mGame;
ISAIAH S
ISAIAH S
1,409 Points

Now it says it's missing a return statement.

Rob Bridges
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points
Rob Bridges
.a{fill-rule:evenodd;}techdegree seal-36
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 Points

Hello, this is still good news. It means we're working through the errors and getting it to work, what error does it toss?

Can you copy it?

ISAIAH S
ISAIAH S
1,409 Points

./Game.java:58: error: missing return statement
}
^
1 error