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Thread: Loop not creating objects

  1. #1
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    Default Loop not creating objects

    Well I'm trying to use a Linked list and i have a Card class and a Node class. In my deck class I want my default constructor to create a deck full of 52 cards. this is what i have so far:
    package project3;
     
    import java.util.LinkedList;
     
    public class Deck {
     
    	private Node front; 
    	private int remainingCards = 52;
    	LinkedList myDeck;
     
    	public Deck()
    	{
    		for(int i = 0; i < 52; i++)
    		{
    			Node temp = front;
    			if(front == null)
    			{
    				front = new Node(new Card(i), null);
    			}
    			else {
    				temp.setNext(new Node(new Card(i), null));
    				temp.getNext();
    			}
    		}
    	}
        public String toString()
        {
        	String output = new String("Cards \n");
        	Node traveller = front;
        	while(traveller.getNext() != null)
        	{
        		output += traveller.getItem() + "\n";
        		traveller = traveller.getNext();
        	}
        	return output;
        }
    }
    In my main class I have this code :
    		Deck xDeck = new Deck();
    		System.out.println(xDeck.toString());
    which only outputs:
    Cards
    King of clubs
    Why isnt the rest of the deck not printing? Or is the deck not being created properly?

    For reference this is my Card class:
    package project3;
     
    /**
     * <p>Title: The Card class</p>
     *
     * <p>Description: This class will represent a single playing card 
     * that has a value between 1 and 13 and a suit (Clubs, Diamonds, 
     * Hearts or Spades).  A card can return its value, suit, point value 
     * or reference to a String containing the cardís value and suit.  It
     * can check to see if two cards have the same value or the same suit.</p>
     * 
     * @author CSC 120 Instructor
     */
    public class Card
    {
        // instance variables
        private int value;
        private String suit;
     
        /**
         * parameterized Card constructor --
         * gets called when an object of the Card class is instantiated 
         * sending a number as an argument -- it determines the value and 
         * suit of the card based upon the number received
         * @param num a number that gets converted to a value between 1 and 
         * 13 and a suit
         */
        public Card(int num)
        {
            int suitNumber;
            value = num % 13;
            if (value == 0)
                value = 13;
            suitNumber = num / 13;
            if (suitNumber == 0)
                suit = "clubs";
            else if (suitNumber == 1)
                suit = "diamonds";
            else if (suitNumber == 2)
                suit = "hearts";
            else if (suitNumber == 3)
                suit = "spades";
            else
                suit = "ERROR";
        }
     
        /**
         * getValue method -- 
         * returns what's stored in the instance variable value
         * @return the state of the instance variable value
         */
        public int getValue()
        {
            return value;
        }
     
        /**
         * getSuit method -- 
         * returns what's stored in the instance variable suit
         * @return a reference to a String that contains the state of the
         * instance variable suit
         */
        public String getSuit()
        {
            return suit;
        }
     
        /** equalValue method --
         * determines if the otherCard's value is the same as this card's value
         * @param otherCard a reference to the Card object (assumes the object 
         * has been instantiated) to compare to this Card object
         * @return true if the values are equal, false if the values are not equal
         */
        public boolean equalValue(Card otherCard)
        {
            if (this.value == otherCard.value)
                return true;
            else
                return false;
        }
     
        /**
         * equalSuit method -- 
         * determines if the otherCards's suit is the same as this card's suit
         * @param otherCard a reference to the Card object (assumes the object 
         * has been instantiated) to compare to this Card object
         * @return true if the suits are the same, false if they are not
         */
        public boolean equalSuit(Card otherCard)
        {
            if (this.suit.equals(otherCard.suit))
                return true;
            else
                return false;
        }
     
        /**
         * toString method --
         * returns the state of the card object
         * @return a reference to a String object that contains the value 
         * and suit of the card
         */
        public String toString()
        {
            if (value == 1)
                return "Ace of " + suit;
            else if (value == 11)
                return "Jack of " + suit;
            else if (value == 12)
                return "Queen of " + suit;
            else if (value == 13)
                return "King of " + suit;
            else
                return value + " of " + suit;
        }
    }
    and this is my Node class:
    package project3;
     
    /**
     * <p>Title: Node Class</p>
     *
     * <p>Description: Defines a node class capable of storing a 
     * reference to an object and a reference to the next node in
     * a linked list. Accessors and mutators are defined for both.</p>
     *
     * @author Darci Burdge
     */
    public class Node
    {
      private Card data; //a reference to an object of type T
      private Node next; //the address of the next node in the list
     
      /**
       * default constructor - initializes data and next to null 
       */
      public Node()
      {
    	  data = null;
    	  next = null;
      }
     
      /**
       * parameterized constructor - initializes data to the user 
       * specified value; next is set to null
       * @param newItem the value to be stored in the node
       */
      public Node(Card newItem)
      {
        data = newItem;
        next = null;
      }
     
      /**
       * parameterized constructor - initializes data and next to user 
       * specified values
       * @param newItem the object reference to be stored in the node
       * @param nextItem the reference to the next node in the list
       */
      public Node(Card newItem, Node nextItem)
      {
        data = newItem;
        next = nextItem;
      }
     
      /**
       * setItem - stores a new value in data
       * @param newItem the object reference to be stored in the node
       */
      public void setItem(Card newItem)
      {
        data = newItem;
      }
     
      /**
       * setNext - stores a new value in next
       * @param nextItem the reference to be stored in next
       */
      public void setNext(Node nextItem)
      {
        next = nextItem;
      }
     
      /**
       * getItem - returns the reference stored in data
       * @return a reference to the data stored in the node
       */
      public Card getItem()
      {
        return data;
      }
     
      /**
       * getNext - returns the reference stored in next
       * @return the reference stored in next
       */
      public Node getNext()
      {
        return next;
      }
    }


  2. #2
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    Default Re: Loop not creating objects

    Part of the problem is that temp.getNext(); is not being put into anything so temp does not change? Possibly other issues, this works though

    	public Deck()
    	{
    		Node temp = new Node(new Card(1), null);
    		front = new Node(new Card(0), temp);
    		for(int i = 2; i < 52; i++)
    		{
    				temp.setNext(new Node(new Card(i), null));
    				temp = temp.getNext();
    		}
    	}

    And your not really using linked list are you?

  3. The Following User Says Thank You to Zula For This Useful Post:

    xecure (October 30th, 2010)

  4. #3
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    Default Re: Loop not creating objects

    Quote Originally Posted by Zula View Post
    Part of the problem is that temp.getNext(); is not being put into anything so temp does not change? Possibly other issues, this works though

    	public Deck()
    	{
    		Node temp = new Node(new Card(1), null);
    		front = new Node(new Card(0), temp);
    		for(int i = 2; i < 52; i++)
    		{
    				temp.setNext(new Node(new Card(i), null));
    				temp = temp.getNext();
    		}
    	}

    And your not really using linked list are you?
    I am using a linked list. well atleast I'm supposed to be.

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