# How to check if a traversion has reached a certain Index in a 2D-Array in Java?

Let’s say we have a 2D-boolean Array as a presentation of a maze, the size of the Array is not fixed and random. The walls are depicted as true:

```boolean[][] mazeArray = new boolean[width][height];
```

The exit of the maze is at a fixed Index. How can I check wether the traversion has reached this certain index or not? My idea was to create an int[ ] to keep track of the position, it gets updated and overwritten with every step:

```int[] location = {1,0};
```

… But I don’t understand why my check in the while-loop doesn’t work:

```while( location != (maze.length-1) && location != (maze.length-2) ) {
// traversion with pledge algorithm
}
```

The problem with your code is that you check wrong items in your `maze` array:

• `maze` is the first “line” of your 2d-array
• `maze` is the second “line” of your 2d-array

Proper way of traversing 2d-array is following (I’ve replaced your `location` array with separate `x` and `y` variables to better visualize the algorithm).

My algorithm enters the 2d `mazeArray` line by line and then iterates each line’s elements.

```public class Maze {
public static void main(String[] args) {
int width = 20;
int height = 20;

boolean[][] mazeArray = new boolean[width][height];

int x = 0;
int y = 0;

while (y < mazeArray.length) {
while (x < mazeArray[y].length) {
System.out.println("Traverse at (" + x + ", " + y + ")");

x += 1;
}

x = 0;
y += 1;
}
}
}

```