Null Pointer Exception

I keep getting a Null Pointer Exception when I run my code. This is the bit that is highlighted.

Code:

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/**Get the random word from the array*/
    public String getWords (){
        String randomWord = words[randy.nextInt(words.length)];
        return randomWord;
    }

---

Code:

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private String[] words = {"apple", "beret", "arose", "along", "beamy", "becks", "decks", "barks",
                              "stark", "start", "stabs", "baggy", "asked", "asset", "asses", "audit",
                              "bowls", "boxes", "seats", "balls", "boats", "boxer", "brick", "bound",
                              "brass", "caked", "braid", "caged", "essay", "fault", "dents", "dutch",
                              "ethos", "dunks", "pains", "faxes", "mummy", "mixer", "mills", "might",
                              "moral", "teeth", "wings", "works", "walls", "tolls", "crawl", "toxin",
                              "bangs", "tough"};

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I don't see any highlighting, but it may be my eyes. I am assuming that the error is on line 3 in your first segment of code? Did you define the randy variable? Do you have access to the words array?

What do you mean, access to the array? That might be my problem. How do you access an array? The bit that is highlighted is

Code:

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String randomWord = words[randy.nextInt(words.length)];

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It is declared private. If it's not in the same class you won't be able to access it without a getter method. I ran the code you have above in a simple test class and it worked fine. It has to be something with your class organization.

What would be a good "getter" method for it? Just like

Code:

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public String getArray(){ return word; }

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or something?

That's fine. However, be careful with your return types.

Usually the getters and setter are the same name as the variables. Like this:

Code:

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public String[] getWords() {
    return words;
}

public void setWords(String[] words) {
    this.words = words;
}

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You have most probably forgot to initialize the words array.

Still throws a NullPointerException.

Code:

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/**
 * TODO:
 * Make it print dashes for the letters.
 * Make it print the letter where index is.
 * Make it continue after start.
 * Add letter to the continue method.
 * Compare random word and selected indexes.
 * Find index of random word, use that index to put the letter into that index
 * then replace the '_' with the letter with that index.
 * Index with Element of the word
 * ...
 */



/** Import necessary packages*/
import java.util.Random;
import javax.swing.JOptionPane;
import java.util.Scanner;
import java.lang.String;

public class Hangman extends BasicGame
{
    /**Call all of the variables*/
    Random randy = new Random();
    private int guesses;
    private final int maxGuesses = 6;
    private String myGeneratedRandomWord = getWords();
    private String letter;
    private String randomWord = "";
    private String itsGuessedLetter = "";
    private String itsSolvedWord = "-----";
    private String[] words = {"apple", "beret", "arose", "along", "beamy", "becks", "decks", "barks",
                              "stark", "start", "stabs", "baggy", "asked", "asset", "asses", "audit",
                              "bowls", "boxes", "seats", "balls", "boats", "boxer", "brick", "bound",
                              "brass", "caked", "braid", "caged", "essay", "fault", "dents", "dutch",
                              "ethos", "dunks", "pains", "faxes", "mummy", "mixer", "mills", "might",
                              "moral", "teeth", "wings", "works", "walls", "tolls", "crawl", "toxin",
                              "bangs", "tough"};
    public String[] getWord(){
        return words;
    }
   
    /**Get the random word from the array*/
    public String getWords (){
        String randomWord = getWord()[randy.nextInt(getWord().length)];
        return randomWord;
    }
   
    /**Get the indexes of the letter of the random word indices don't start with 1*/
    public String getSelected(){
        return itsGuessedLetter;
    }
   
    /**Finds index of the letter of randomWord*/
    public int getIndex(){
        int index = getWords().indexOf(getSelected());
        return index;
    }
   
    /**Get the first input, set strikes to zero, get the random word*/
    public void start(){
        guesses = 0;
        getWords();
        JOptionPane.showMessageDialog(null, "Your word is: " +itsSolvedWord);
        itsGuessedLetter = JOptionPane.showInputDialog(null, "Make your guess!");
        int index = myGeneratedRandomWord.indexOf(itsGuessedLetter);
        if(myGeneratedRandomWord.indexOf(itsGuessedLetter ) != -1) {
            // it contains the letter
            if(index >= 0){
                itsSolvedWord = itsSolvedWord.substring(0,index)+itsGuessedLetter+itsSolvedWord.substring(index + 1);
                JOptionPane.showMessageDialog(null, "Updated word: " +itsSolvedWord);
            }
      }
      else {
            // wrong guess
            guesses++;
      }
    }
   
    /**Continue the game on, checks if the letter is there if not then apply the letter*/
    public void continueGame(){
      itsGuessedLetter = JOptionPane.showInputDialog(null, "Make another guess!");
      int index = myGeneratedRandomWord.indexOf(itsGuessedLetter);
      if(myGeneratedRandomWord.indexOf(itsGuessedLetter ) != -1) {
            // it contains the letter
            itsSolvedWord = itsSolvedWord.substring(0,index)+itsGuessedLetter+itsSolvedWord.substring(index + 1);
      }
      else {
            // wrong guess
            guesses++;
      }
    }
   
    /** Runner basically*/
    public void mainScreen (){
        start();
        while (guesses != maxGuesses){
            continueGame();
            checkBodyParts();
        }
        gameOver();
    }
   
    /**Gets the */
   
   
    /**After certain strikes head is called etc.*/
    public void checkBodyParts(){
        if(guesses == 1){
            JOptionPane.showMessageDialog(null, "You now have a head! Wrong guesses left: 5");
        }
        if(guesses == 2){
            JOptionPane.showMessageDialog(null, "You now have a body! Wrong guesses left: 4");
        }
        if(guesses == 3){
            JOptionPane.showMessageDialog(null, "You now have a right arm! Wrong guesses left: 3");
        }
        if(guesses == 4){
            JOptionPane.showMessageDialog(null, "You now have a left arm! Wrong guesses left: 2");
        }
        if(guesses == 5){
            JOptionPane.showMessageDialog(null, "You now have a right leg! Wrong guesses left: 1");
        }
        if(guesses == maxGuesses){
            JOptionPane.showMessageDialog(null, "You lose!");
        }
    }
   
    /**You lose.*/
    public void gameOver(){
        JOptionPane.showMessageDialog(null, "Game Over!");
        System.exit(0);
    }
}

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Can you provide the whole error?

Code:

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java.lang.NullPointerException
        at Hangman.getWords(Hangman.java:46)
        at Hangman.<init>(Hangman.java:28)
        at GameApp.main(GameApp.java:9)

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You don't need the

Code:

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public String[] getWord(){
        return words;
    }

---

because the words array is visible to the class. You don't need a getter. You need to debug a bit. Try separating line 46 into different segments.

You get this error because your variable words is null. Like I said above, you need to initialize the variable.

How do I initialize it??? Everything I go through it says it's initialized.

Follow the code from the top to the bottom and see if you can find the error.

Quote:

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Originally Posted by Army

How do I initialize it??? Everything I go through it says it's initialized.

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Read through this: Lesson: Language Basics (The Java™ Tutorials > Learning the Java Language)

Really, if you know where it is just tell me. I've had this problem for two weeks now and I'm pretty tiered of it.

Quote:

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Originally Posted by PhQ

Read through this: Lesson: Language Basics (The Java™ Tutorials > Learning the Java Language)

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Alternatively, you can use the shortcut syntax to create and initialize an array:

int[] anArray = {
100, 200, 300,
400, 500, 600,
700, 800, 900, 1000
};

Tells me nothing.

Look at the order you are trying to access the array at

Code:

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private String myGeneratedRandomWord = getWords();

---

See anything wrong with that being there?

Quote:

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Originally Posted by Wnt2bsleepin

Look at the order you are trying to access the array at

Code:

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private String myGeneratedRandomWord = getWords();

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See anything wrong with that being there?

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Ah, ok, thanks. It works now XD