Getting The String Contains Method to Work In My Code

Question

I was asked to develop a game that involves characters exploring a world. The world is a 2D array. The player starts in some cell in the array and progresses to the next level by reaching any cell on the edge of the array. On each turn, a player can move north, south, east or west. However the player cannot move back to a cell it has already visited. I must use the string contains method for this. My code keep giving me an array out of bounds error string index out of range -1. I have no idea why it is doing this. I would really appreciate some help on this to make it work. Thank you so much. This code is written in java using Netbeans. I need my string contains method to work.

The error happens on this line: String bestdirection = path.substring(0,commaIdx);

Here is the whole code:

 public static void main(String[] args) {
    // TODO code application logic here
    //making array 
 Scanner scanner = new Scanner(System.in);
    System.out.print("How many rows are in the maze? ");
int rows = scanner.nextInt();
    System.out.print("How many colums are in the maze? ");
int colums = scanner.nextInt();
int [][] maze = new int [rows][colums];
for (int i = 0; i< maze.length; i++){
    System.out.print("Enter the danger in row " + (i+1) + ", separated by spaces: ");
    for (int j=0; j<maze[i].length; j++){



    maze[i][j] = scanner.nextInt();


}

}
           System.out.print("Enter the starting x coordinate: ");
    int x = scanner.nextInt();
    System.out.print("Enter the starting y coordinate: ");
    int y = scanner.nextInt();
    System.out.println("Moving to " + x + "," + y + "(danger level " + maze[x][y] + ")");
    String path = (Integer.toString(x) + Integer. toString(y));
    for ( int i=0; i<maze.length; i++){
        for( int j=0; j<maze[i].length; j++){
            if (x == i && y == j){
                System.out.print("*");

            }
            else{ 
                System.out.print(maze[i][j] + " ");
            }


        }
        System.out.println("");
    }

    while (x !=0 && y!=0 && x !=(rows -1) && y != (colums -1)){
    int left = maze[x][y-1];
    int right = maze[x][y+1];
    int up = maze[x-1][y];
    int down = maze[x+1][y];
    int commaIdx = path.indexOf(",");
    String bestdirection = path.substring(0,commaIdx);
   String bestdirection2 = path.substring(commaIdx);

   // if ( x == x && y == y+1){
      // left=1000;
  //  }
    //int count=0;
    if (left < right && left < up && left< down && !path.contains(path)){
        y = y-1;
         System.out.println("Moving to " + x+ "," + y + " (danger level " + maze[x][y] + ")" );
        for (int i =0; i<maze.length; i++ ){
            for (int j=0; j<maze[i].length; j++){

            if (x ==i && y==j){
                System.out.print("*");

            }
            else {
                System.out.print(maze[i][j] + " ");
            }
                System.out.println("");
            }

       // System.out.println("Moving to " + x + y + " (danger level " + maze[x][y] + ")" );
       // count++;

    }
       // if (x ==x && y ==(y-1)){
           // right =1000;
       // }

     if(right < left && right < up && right < down && !path.contains(path)){
        y= y+1;



        }
   // if (x == (x-1) && y==y){
        //up= 1000;
   // }
     if (up < right && up < left && up < down && !path.contains(path)){
        x = x-1;


    } 
    //if (x == (x+1) && y==y){
      //  down = 1000;
   // }
     if (down < right && down < left && down < up && !path.contains(path)){
        x = x+1;


    }
    }
    }


   // int total = maze[x][y] + maze[x][y];

    if (x ==0 || y ==0 || x == (rows -1) || y== (colums -1)){

        for (int i =0; i< maze.length; i++ ){
            for (int j=0; j<maze[i].length; j++){
                if (x ==i && y==j){
                    System.out.println("*");
                }
                else{
                    System.out.println(maze[i][j] + " ");
                }
            }
            System.out.println("");
        }
        System.out.println("Exited the world at: " + x + "," + y + " total danger faced: " );


        }
    }

    }

If you want people to try and read your code, indent it properly — khelwood
– khelwood, Commented Oct 27, 2017 at 23:33

user3437460 · Accepted Answer · 2017-10-27 23:27:49Z

1

That is because your String variable path does not contain a comma , which will return you an index of -1 in:

int commaIdx = path.indexOf(",");

Thus causing the StringIndexOutOfBoundsException when you run

String bestdirection = path.substring(0,commaIdx);

Check and make sure your commaIdx has a valid value first.

answered Oct 27, 2017 at 23:27

user3437460

17.5k18 gold badges67 silver badges110 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Harshvardhan Joshi · Accepted Answer · 2018-06-22 07:27:01Z

1

I think you forgot to add "," when you create path variable. The problem might be solved after you add the comma in the string as below:

String path = (Integer.toString(x) + "," + Integer.toString(y));

answered Jun 22, 2018 at 7:27

Harshvardhan Joshi

3,2032 gold badges22 silver badges32 bronze badges

Collectives™ on Stack Overflow

Getting The String Contains Method to Work In My Code

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related