Using a method from an ArrayList

Question

So I'm making this program that's essentially a maze game and I'm stuck on a few small pieces of code. First let me go over a few things:
-there is an abstract class Occupant
-2 classes: Explorer and RandomOccupant extend Occupant
-2 classes: Treasure and Monster extend RandomOccupant
-Treasure has a method public boolean found() which returns the value of its instance variable found.
-the class with the method shown below initializes an ArrayList of RandomOccupants
Here's the piece of code I'm having problems with. This piece of code is in another class Maze with is does not extend or implement any others, simply uses them.
private boolean foundAllTreasures()
        boolean foundAll = true;
        int i = 0;
        // DONE_____________________CHANGE - search through all the occupants to see if the Treasures have been found.  Return false if
        //        - there is a Treasure that hasn't been found.
        while(i < randOccupants.size()){
            if((randOccupants.get(i) instanceof Treasure) && !(randOccupants.get(i).found())){
                 foundALL = false;
               i++;
        return foundAll;
    }The part I'm having trouble with is the 2nd condition of the if-statement. How can I rewrite the if statement so that I can call the found() method of the Treasure class?
Edited by: sublimeph03nix on Feb 8, 2009 7:12 PM

Answer 1

You need to cast the object retrieved from the ArrayList to a Treasure object before you can call found.
BTW I don't think this method will do what you want. All it will do is return "found" of the last object in the List.
eg:
public static boolean areAllFive(int[] arr) {
    boolean allFive = false;
    for(int i : arr) {
        if(i == 5) {
            allFive = true;
        } else {
          allFive = false;
    return allFive;
public static void main(String[] args) {
    int[] nums = {1,2,3,4,5};
    if(areAllFive(nums)) {
        System.out.println("All the numbers in the array are 5");
}