Tryin to create a deck of cards

[mrbrendano]

Hey!

Im tryin to create a deck of cards and im having a bit of trouble.

I have a card class with a string to represent the suit and an int for the value of the card.
I have setters and getters for both.

Then I have a deck class with a card array to hold the deck.

Im having trouble generating the deck of cards tho.

my code for generating the desk is;

public card[] generateDeck(card c){
c=new card();
int value=2;                                  //value of first card is two. Up to 15 for one suit
for(int j=0;j<12;j++){                     //13 cards in a suit          
c.setSuit("hearts");
c.setValue(value);
deck[j]=c;
value++;
}
}

My problem is that the card value is not increasing. Its just stayin the same no matter what i seem to do. Any advice would be great!!

Thanks

[KevinWorkman]

Well, when are you increasing the integer that value stores?

[mrbrendano]

Well, when are you increasing the integer that value stores?

value++ no??

I tried another way there but still didnt work. I created an increaceValue method in the card class and called that in the loop but didnt work either!!

[KevinWorkman]

Oi sorry, I don't know how I missed that. It'd be easier to help you if you provided an SSCCE that demonstrated the problem, as that piece of code looks pretty kosher by itself.

[mrbrendano]

ok here goes. 3 classes. deck, card and test(main).

public class deck {

	card[] deck = new card[52];
	
	public card[] genDeck(card c){
		c=new card();
		String suit="hearts";
		int value=2;
		for(int j=0;j<=12;j++){
		c.setSuit(suit);
		c.setValue(value);
		deck[j]=c;
		value++;
		}
		return deck;
	}
	
}

card class

public class card {
	private String suit;
	private int value;
	
	public void setSuit(String s){
		suit=s;
	}
	public void setValue(int v){
		value=v;
	}
	public String getSuit(){
		return suit;
	}
	public int getValue(){
		return value;
	}
	
}

and finally the test

public class test {

	public static void main(String[]args){
		card c = new card();
		deck newDeck = new deck();
		
		card[] list=newDeck.genDeck(c);
		for(int j=0;j<list.length;j++){
			System.out.println(list[j].getSuit()+list[j].getValue());
		}
	}
}

this is the output. The nullpointer I can handle. Its the number im having trouble with

hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
hearts14
Exception in thread "main" java.lang.NullPointerException
at test.main(test.java:10)

[KevinWorkman]

Here is more of an SSCCE:

public class Test {

	public static class Deck {

		Card[] deck = new Card[52];

		public Card[] genDeck(Card c){
			c = new Card();
			String suit="hearts";
			int value=2;
			for(int j=0;j<=12;j++){
				c.setSuit(suit);
				c.setValue(value);
				deck[j]=c;
				value++;
			}
			return deck;
		}

	}

	public static class Card {
		private String suit;
		private int value;

		public void setSuit(String s){
			suit=s;
		}
		public void setValue(int v){
			System.out.println(v);
			value=v;
		}
		public String getSuit(){
			return suit;
		}
		public int getValue(){
			System.out.println("r: " + value);
			return value;
		}

	}

	public static void main(String[]args){
		Card c = new Card();
		Deck newDeck = new Deck();

		Card[] list=newDeck.genDeck(c);
		
		for(int j=0; j<list.length; j++){
			System.out.println(list[j].getSuit()+list[j].getValue());
		}
	}
}

In any case, your problem is that you only ever have one instance of Card (notice how class names start with an upper-case letter). Each time through the loop, you're updating its value and then adding it to the array. But it's the SAME instance of Card, so you're updating EVERY Card that's been added to the array.

One solution would be to create a new Card each iteration of the loop and add that to the array instead.

[mrbrendano]

Oh right. I wasnt sure how exactly you wanted it. Il know for next time! I will also start putting a capitol for the start of the class.

i moved the c=new card() into the loop and it sorted my problem right out.

Thanks very much Kevin