Question

I am making a maze solver. For some reason Everytime the line marked with ‘–>’ is reached, “Enter height: ” is outputted. It is like that line (which is not run when it is reached) somehow makes the method loop.

private void makeMap() {
    Map map; //used to convert the char array into a graph
    int height; //the height of the map by user input
    char[][] array; //used to store the char map

    System.err.println("Enter height: ");
    height = scanner.nextInt(); //gets and stores the height from the user

    array = new char[height][]; //initializes the map with input height
    for(int i=0; i<height; i++) { //adds row by row to the map array
        System.err.print("Enter next line of map: ");
        array[i] = scanner.next().toCharArray();
    }

    --> map = new Map(array); //initializes the map by passing the char array

    graph = map.makeGraph(); //creates a graph from the char array
  }

I labelled with ‘–>’ where I believe my problem lays. Any code i put before the marked line will execute, but as soon as that line is reached it loops back to the top of this method. Below is the Map constructor:

public Map(char[][] passMap) {
    adjList = new Vertex[map.length*map[0].length];
    map = passMap; //stores the passed map
}

ANY HELP is better than no help. I’ve been at this for hours. Thanks.

Answer 1

Your map variable is probably uninitialized. Change:

adjList = new Vertex[map.length*map[0].length];

To:

adjList = new Vertex[passMap.length*passMap[0].length];

I would also change your System.err.println() calls to System.out.println(). The first one is for error output, and the second one for normal console output.