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Start your free trialHector Torres
4,802 PointsCan't solve this error....
Exception in thread "main" java.lang.NullPointerException
at Game.getRemainingTries(Game.java:35) >>> return MAX_MISSES - mMisses.length();
at Prompter.play(Prompter.java:10) >>> while (mGame.getRemainingTries() > 0) {...
at Hangman.main(Hangman.java:6 >>> prompter.play();
Any ideas why?
Hangman.java
public class Hangman {
public static void main(String[] args) {
Game game = new Game("treehouse");
Prompter prompter = new Prompter(game);
prompter.play();
}
}
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();
String guessAsString = console.readLine("Enter a letter: ");
char guess = guessAsString.charAt(0);
return mGame.applyGuess(guess);
}
public void displayProgress() {
System.out.printf("You have %d tries to solve: %s\n",
mGame.getRemainingTries(),
mGame.getCurrentProgress());
}
}
Game.java
public class Game {
public static final int MAX_MISSES = 7;
private String mAnswer;
private String mHits;
private String mMisses;
private String letter;
public Game(String answer) {
mAnswer = answer;
}
public boolean applyGuess(char 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();
}
}
EDIT: Added the code posts to original question for better readability. - Dane E. Parchment Jr. (Moderator)
1 Answer
Alfred Lindal Haug
1,231 PointsIt seems that you're trying to reference your variables from the Game-class without instantiating them. A simple fix is maybe instantiating them with "". (private String whateverVariable = "";) . This seems to work in console for me, but for some reason my IDE still gives me errors.
Hector Torres
4,802 PointsThanks.
Brendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsBrendan Whiting
Front End Web Development Techdegree Graduate 84,738 PointsCan you post your code?