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Thread: nullPointerException

  1. #1
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    Question nullPointerException

    hi, i'm getting constructor null pointer exception but i don't know what has gone wrong...

    private int capacity; // maximum capacity of the board
    	private double minimum; // minimum distance of the flyer
    	private SortedLinkedList sortedList;
    	private int size = 0;
     
    	public ScoreBoard() {
    		capacity = 10;
    		minimum = 0.0;
    		sortedList = new SortedLinkedList();
    	}
     
    	public ScoreBoard(int capacity) {
    		this.capacity = capacity;
    		minimum = 0.0;
    		sortedList = new SortedLinkedList(capacity);
    	}
     
    	public ScoreBoard(double minimum) {
    		this.minimum = minimum;
    		capacity = 10;
    		sortedList = new SortedLinkedList();
    	}
     
    	public ScoreBoard(int capacity, double minimum) {
    		this.capacity = capacity;
    		this.minimum = minimum;
    		sortedList = new SortedLinkedList(capacity);
    	}


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    Default Re: nullPointerException

    Post the full text of the error message and stack trace which will include code line numbers, then indicate which line in the code you posted is the last line number mentioned in the error message, the location of the NPE.

    OR, post runnable code that demonstrates the problem.

    OR, to debug the code yourself, you could:

    - add prints to your code to determine which of the objects in the line indicated by the error message is null and work backwards to determine why that object was not initialized properly.

    - use a debugger to accomplish the same as the previous suggestion.

  3. #3
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    Default Re: nullPointerException

    it's an assignment and the feedback was just nullPointerException for constructor. it's alright... i think i should give up amending it. i need to study for tomorrow's test thx anyway!

  4. #4
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    Default Re: nullPointerException

    Well, the feedback isn't very helpful, and I don't see an NPE in what you've posted. I assume those are 4 constructors for the class ScoreBoard.

    Good luck on your test!

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