Need help with ArrayList loop

Hey everyone, I've been stuck on this problem for a long time. I can't seem to get my last method to return anything. It's supposed to add all of the unsold lots of an auction (if the highestBid == null) to an ArrayList, then at the end of the method it's supposed to return that list. My teacher told me to look closely at the header for the last for-each loop, but I still can't figure out what's wrong with it. Any help is much appreciated.

Code :

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import java.util.ArrayList;
 
/**
 * A simple model of an auction.
 * The auction maintains a list of lots of arbitrary length.
 *
 * @author David J. Barnes and Michael Kolling.
 * @version 2008.03.30
 */
public class Auction
{
    // The list of Lots in this auction.
    private ArrayList<Lot> lots;
    // The number that will be given to the next lot entered
    // into this auction.
    private int nextLotNumber;
    //Edit
    //Matthew Slagle, June 3, 2012
    //The list of unsold lots in this auction.
    private ArrayList<Lot> getUnsold;
 
    /**
     * Create a new auction.
     */
    public Auction()
    {
        lots = new ArrayList<Lot>();
        nextLotNumber = 1;
    }
 
    /**
     * Enter a new lot into the auction.
     * @param description A description of the lot.
     */
    public void enterLot(String description)
    {
        lots.add(new Lot(nextLotNumber, description));
        nextLotNumber++;
    }
 
    /**
     * Show the full list of lots in this auction.
     */
    public void showLots()
    {
        for(Lot lot : lots) {
            System.out.println(lot.toString());
        }
    }
 
    /**
     * Bid for a lot.
     * A message indicating whether the bid is successful or not
     * is printed.
     * @param number The lot number being bid for.
     * @param bidder The person bidding for the lot.
     * @param value  The value of the bid.
     */
    public void bidFor(int lotNumber, Person bidder, long value)
    {
        Lot selectedLot = getLot(lotNumber);
        if(selectedLot != null) {
            boolean successful = selectedLot.bidFor(new Bid(bidder, value));
            if(successful) {
                System.out.println("The bid for lot number " +
                                   lotNumber + " was successful.");
            }
            else {
                // Report which bid is higher.
                Bid highestBid = selectedLot.getHighestBid();
                System.out.println("Lot number: " + lotNumber +
                                   " already has a bid of: " +
                                   highestBid.getValue());
            }
        }
    }
 
    /**
     * Return the lot with the given number. Return null
     * if a lot with this number does not exist.
     * @param lotNumber The number of the lot to return.
     */
    public Lot getLot(int lotNumber)
    {
        if((lotNumber >= 1) && (lotNumber < nextLotNumber)) {
            // The number seems to be reasonable.
            Lot selectedLot = lots.get(lotNumber - 1);
            // Include a confidence check to be sure we have the
            // right lot.
            if(selectedLot.getNumber() != lotNumber) {
                System.out.println("Internal error: Lot number " +
                                   selectedLot.getNumber() +
                                   " was returned instead of " +
                                   lotNumber);
                // Don't return an invalid lot.
                selectedLot = null;
            }
            return selectedLot;
        }
        else {
            System.out.println("Lot number: " + lotNumber +
                               " does not exist.");
            return null;
        }
    }
 
    /**
     * Ex. 4.28
     * Matthew Slagle
     * May 28, 2012
     * Prints out a list of all lots and their info.
     */
    public void close()
    {
        for(Lot lot : lots)
        {
            int number = lot.getNumber();
            System.out.println("Lot Number: " + number);
 
            String lotName = lot.getDescription();
            System.out.println(lotName);
 
            Bid highestBid = lot.getHighestBid();
            if (highestBid != null)
            {
                System.out.println("Winner: " + highestBid.getBidder().getName());
                System.out.println("Highest Bid: " + highestBid.getValue());
                System.out.println();
            }
            else
            {
                System.out.println("This lot has not been sold.");
            }
        }
    }
 
  /**
     * Ex 4.29
     * Matthew Slagle
     * May 28, 2012
     * Displays the unsold lots
     * If no lots are unsold, it lets the user know.
     */
    public ArrayList<Lot> getUnsold()
    {
      ArrayList<Lot> unsoldLots = new ArrayList<Lot>();
      for(Lot lot : unsoldLots)
      {
          int number = lot.getNumber();
          String lotName = lot.getDescription();
          Bid highestBid = lot.getHighestBid();
 
          if (highestBid == null)
          {
              unsoldLots.add(new Lot(number, lotName));
            }
            nextLotNumber++;
        }
        System.out.println(unsoldLots);
        return unsoldLots;
    }
 
 
}

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Hello mattslagle44!
There are some classes missing so it's difficult to say what's going on with your code but there is a problem with your logic in your getUnsold() method.

Code Java:

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ArrayList<Lot> unsoldLots = new ArrayList<Lot>();
for(Lot lot : unsoldLots){ 
    // ...
}

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In the above piece of code you create an new ArrayList which is -by default- empty. And then you run through it to do something. Can you see the problem now?
And please edit your post and wrap your code in code tags.
Hope this helps.

I see that now, thanks. I set unsoldLots to equal a new list, looked for values in the empty list, then returned the empty list.

Yep. Instead just use your lots ArrayList rather than creating a new object.