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Java Java Objects (Retired) Creating the MVP Prompting for Guesses

Posted by sldknflskdngd
sldknflskdngd
9,985 Points

What is going on?

I tried to run on IntellJ and this is what I got

Prompter.promptForGuess(Prompter.java:15) at nyc.c4q.personabe1984.Hangman.main(Hangman.java:10) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

then when I tried to run console I got

javac Hangman.java && java Hangman Hangman.java:7: error: cannot find symbol Game game = new Game("Treehouse"); ^ symbol: class Game location: class Hangman Hangman.java:7: error: cannot find symbol Game game = new Game("Treehouse"); ^ symbol: class Game location: class Hangman Hangman.java:9: error: cannot find symbol Prompter prompter = new Prompter(game); ^ symbol: class Prompter location: class Hangman Hangman.java:9: error: cannot find symbol Prompter prompter = new Prompter(game); ^ symbol: class Prompter location: class Hangman 4 errors Hans (master *+) personabe1984 $ javac Game.java Hans (master *+) personabe1984 $ javac Prompter.java Prompter.java:8: error: cannot find symbol private Game mGame; ^ symbol: class Game location: class Prompter Prompter.java:10: error: cannot find symbol public Prompter(Game game){ ^ symbol: class Game location: class Prompter 2 errors

9 Answers

Ryan Blakeney
Ryan Blakeney
8,870 Points

Alright so, i am literally in the same spot and i literally had the exact issue. It was answered in this thread: https://teamtreehouse.com/community/how-to-fix-javalangnullpointerexception

You need to import a scanner and replace the console with scanner and it works perfect.

  Scanner console = new Scanner(System.in);
        System.out.println("Enter a letter: ");
        String guessAsString = console.nextLine();
Ryan Blakeney
Ryan Blakeney
8,870 Points
Ryan Blakeney
Ryan Blakeney
8,870 Points

Can you please post your code?

sldknflskdngd
sldknflskdngd
9,985 Points
sldknflskdngd
sldknflskdngd
9,985 Points

public class Hangman {

public static void main(String[] args){

    Game game = new Game("Treehouse");

    Prompter prompter = new Prompter(game);
    boolean isHit = prompter.promptForGuess();

    if(isHit){
        System.out.println("is a hit");
    }else{
        System.out.println("is a miss");
    }
}

}

sldknflskdngd
sldknflskdngd
9,985 Points
sldknflskdngd
sldknflskdngd
9,985 Points

import java.io.Console;

public class Prompter {

private Game mGame;

public Prompter(Game game){
    mGame = game;
}

public boolean promptForGuess(){
    Console console = System.console();
    String guessAsString = console.readLine("Enter a letter:   ");
    char guess = guessAsString.charAt(0);
    return mGame.applyGuesses(guess);
}

}

sldknflskdngd
sldknflskdngd
9,985 Points
sldknflskdngd
sldknflskdngd
9,985 Points

public class Game { private String mAnswer; private String mHits; private String mMisses;

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

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

}

sldknflskdngd
sldknflskdngd
9,985 Points
sldknflskdngd
sldknflskdngd
9,985 Points

The console object is not sitting well when I run it on intelliJ so when I tried to do it on terminal I still get the errors above.

sldknflskdngd
sldknflskdngd
9,985 Points
sldknflskdngd
sldknflskdngd
9,985 Points

Thanks. That solved the problem. But do you know why we cannot use the Console object?

sldknflskdngd
sldknflskdngd
9,985 Points
sldknflskdngd
sldknflskdngd
9,985 Points

never mind apparently even with the import the Console object is not available on IDE. So strange.

Ryan Blakeney
Ryan Blakeney
8,870 Points
Ryan Blakeney
Ryan Blakeney
8,870 Points

Because we are not running the program in the Console, we are running it in the IDE. Its explained in that thread better than i could explain it.