Thread: Need help with Gridworld

I'm writing a Chess program in Gridworld, and I'm running into a bit of a problem coming up with a line of code that checks if a location is occupied or not. Right now, I am using

if((getGrid().isValid(l1) == true && getGrid().get(l1) != null))

, but this isn't working. Any help would be greatly appreciated. Thank you!

Please elaborate on what you mean by "isn't working." If there are error messages, please post here the messages in their entirety. Also, the single line of code you posted is not sufficient for anyone to be able to tell if there's a problem with it.

    public ArrayList<Location> getAttackLocations()
    {
        ArrayList<Location> moves = new ArrayList<Location>();
        ArrayList<Location> possibleMoves = new ArrayList<Location>();
 
        for(Location l : moves)
        {
            if(getGrid().get(l) != null)
            {
                moves.add(l);
            }
        }
 
        return moves;
    }

This is the method, and this is the method it is referencing

public ArrayList<Location> getMoveLocations()
    {
        ArrayList<Location> moves = new ArrayList<Location>();
 
        boolean canContinue = true;
        int numSpacesMoved = 1;
        Location l = getLocation();
        while(canContinue)
        {
            Location l1 = new Location(l.getRow() - numSpacesMoved, l.getCol() - numSpacesMoved);
            if(getGrid().isValid(l1) == true)
            {
                moves.add(l1);
                numSpacesMoved++;
            }
            else
            {
                canContinue = false;
            }
        }
        canContinue = true;
        numSpacesMoved = 1;
        while(canContinue)
        {
            Location l1 = new Location(l.getRow() + numSpacesMoved, l.getCol() + numSpacesMoved);
            if(getGrid().isValid(l1) == true)
            {
                moves.add(l1);
                numSpacesMoved++;
            }
            else
            {
                canContinue = false;
            }
        }
        canContinue = true;
        numSpacesMoved = 1;
        while(canContinue)
        {
            Location l1 = new Location(l.getRow() + numSpacesMoved, l.getCol() - numSpacesMoved);
            if(getGrid().isValid(l1) == true)
            {
                moves.add(l1);
                numSpacesMoved++;
            }
            else
            {
                canContinue = false;
            }
        }
        canContinue = true;
        numSpacesMoved = 1;
        while(canContinue)
        {
            Location l1 = new Location(l.getRow() - numSpacesMoved, l.getCol() + numSpacesMoved);
            if(getGrid().isValid(l1) == true)
            {
                moves.add(l1);
                numSpacesMoved++;
            }
            else
            {
                canContinue = false;
            }
        }
        return moves;
    }

The getMoveLocations() method is working fine, but whenever I try the getAttackLocations() method, it just pulls up an empty ArrayList