Question

I’m coding a simple maze game in java. The program reads in a text “map” from an input file for the layout of the maze. The rules are simple: navigate the maze (represented by a 2D array) through user input and avoid the cave-ins (represented by Xs), and get to the ‘P’ (player) the the spot marked ‘T’. Right now, I’ve got most of the code written, it’s just a matter of getting it to work properly. I’ve set up most of the game to run with a while loop, with the boolean “got treasure” set to false. Once this rings true, it should end the game.

However, I haven’t coded the circumstance in which the player actually gets the treasure though, so I’m wondering why my code simply spits out “Congratulations! You’ve found the treasure!” and nothing else. If anyone could shed some light on this, I’d be very grateful. My code is somewhat of a mess of loops, as our teacher has just gotten to methods, constructors, and creating our own classes. Here is the code I have so far:

import java.util.*;
import java.io.File;
public class MazeGame {

public static void main(String[] args) throws Exception {
    Scanner scan = new Scanner(new File("maze.txt"));
    Scanner user = new Scanner(System.in);
    int rows = scan.nextInt();
    int columns = scan.nextInt();
    int px = 0;
    int py = 0;
    String [][] maze = new String[rows][columns];
    String junk = scan.nextLine();

    for (int i = 0; i < rows; i++){
        String temp = scan.nextLine();
        String[] arrayPasser = temp.split("");
        for (int j = 0; j < columns; j++){
            maze[i][j] = arrayPasser[i];
        }
    }

    boolean gotTreasure = false;

    while (gotTreasure = false){
        for (int i = 0; i < rows; i++){
            for (int j = 0; j < columns; j++){
                System.out.print(maze[i][j]);
                System.out.print(" ");
        }
            System.out.print("\n");
      }


        System.out.printf("\n");
        System.out.println("You may:");
        System.out.println("1) Move up");
        System.out.println("2) Move down");
        System.out.println("3) Move left");
        System.out.println("4) Move right");
        System.out.println("0) Quit");
        int choice = user.nextInt();
        int i = 0;

        if (choice == 1 && i >= 0 && i < columns){
            for (int k = 0; k < rows; k++){
                for (int l = 0; l < columns; l++){
                    if (maze[k][l].equals(maze[px][py]) && maze[px][py-1].equals("X") == false){
                        maze[px][py] = ".";
                        maze[k][l-1] = "P";
                        maze[px][py] = maze[k][l-1];
                    }else if (maze[px][py-1] == "X"){
                        System.out.println("Cannot move into a cave-in! Try something else.");
                    }else {
                    continue;}


                    }
                }
            }
        else if (choice == 2 && i >= 0 && i < columns){
            for (int k = 0; k < rows; k++){
                for (int l = 0; l < columns; l++){
                    if (maze[k][l].equals(maze[px][py]) && maze[px][py+1].equals("X") == false){
                        maze[px][py] = ".";
                        maze[k][l+1] = "P";
                        maze[px][py] = maze[k][l+1];
                    }else if (maze[px][py+1] == "X"){
                        System.out.println("Cannot move into a cave-in! Try something else.");
                    }else {
                    continue;}

               }
             }
            }
        else if (choice == 3 && i >= 0 && i < columns){
            for (int k = 0; k < rows; k++){
                for (int l = 0; l < columns; l++){
                    if (maze[k][l].equals(maze[px][py]) && maze[px-1][py].equals("X") == false){
                        maze[px][py] = ".";
                        maze[k-1][l] = "P";
                        maze[px][py] = maze[k-1][l];
                    }else if (maze[px-1][py] == "X"){
                        System.out.println("Cannot move into a cave-in! Try something else.");
                    }else {
                    continue;}
                }
            }
        }
        else if (choice == 4 && i >= 0 && i < columns){
            for (int k = 0; k < rows; k++){
                for (int l = 0; l < columns; l++){
                    if (maze[k][l].equals(maze[px][py]) && maze[px+1][py].equals("X") == false){
                        maze[px][py] = ".";
                        maze[k+1][l] = "P";
                        maze[px][py] = maze[k+1][l];
                    }else if (maze[px+1][py] == "X"){
                        System.out.println("Cannot move into a cave-in! Try something else.");
                    }else {
                    continue;}
                }
            }
        }
        else if (choice == 0){
            System.exit(0);
        }
    }

    System.out.println("Congratulations, you found the treasure!");

    scan.close();
    user.close();
        }

    }

And here is the sample input file:

• 5 5
• P.XX.
• .X…
• …X.
• XXT..
• ..X..

Answer 1

(sigh) one equals sign instead of two. You have “while (gotTreasure = false)”, which assigns the value false to gotTreasure and does not enter the loop. Change it to “while (gotTreasure == false) and it enters the loop.

For future questions: please attempt to figure out on your own what is happening, and let others know what you have tried and what specific questions you have about it. It is arguable I should just have let this go, since it is essentially a request to debug your code for you. Learn to debug yourself. If trace statements aren’t getting executed, it’s most likely the code at that point isn’t getting executed. If a loop isn’t getting entered, it is almost certainly because the conditions for entering the loop don’t exist.

Learn to use a debugger – eclipse (and, I am sure, lots of other development tools) has an excellent one. Find out what a breakpoint is, how to set it and examine variables when it is hit, and figure out from there what has gone wrong.