Passing objects as parameters[Java]

[Cinjection]

Ok. I'm making a game of poker in Java. I have several class including one called Card. This clas contains card information about one card. So then in theory, there will be 9 Card objects in the game/per round. Thats fine.

Here's my problem, I need to pass the Card object around to do various things (checking for conbinations of cards, checking for duplicate card, etc). When I pass my object (or print it out), I get null. Clearly i'm doing something wrong. Here the one of the problem methods:

code:

private void dealHands(){ Card [] handCards = new Card[4]; //Array to hold the four cards boolean isDuplicate = true; //The code block below ensures that duplicate cards have not been generated. for (int c = 0; c < 4; c++){ //Loops through the handCards array. isDuplicate = true; while(isDuplicate){ //Loops through each card until a non-duplicate is selected if ( gameTable.checkDuplicate( handCards[c] ) ){ //Checks to see if the card generated has already been drawn handCards[c].regenerateValues(); } else { gameTable.updateDuplicateList( handCards[c] ); isDuplicate = false; } //End isDupilicate if check }//End isDuplicate while check } //End handCards Loop //Assigns the cards to the players. By this point, cards generated are non-duplicates user.addCardsToHand( handCards[0], handCards[2] ); theBot.addCardsToHand( handCards[1], handCards[3] ); //Add the AI hand cards to AI database (Hippcampas/brain) brain.addAICards( handCards[1], handCards[3] ); //Output the user's cards System.out.println("The two cards you draw are:"); System.out.println( handCards[0].readYourself() ); System.out.println( handCards[2].readYourself() ); }//End dealHands

The card values (suit and numbered value) gets determined on creating by the constructer. If it's a duplicate, I call a method in Card to regenerate the card values.

Unfortunetly, every time I print out or pass handCards[c], i get a null value. And of course when i'm playing with a null object, i get a null pointer exepetion. The call to checkDuplicate always has a null parameter.

Could someone please explain to me what i'm doing wrong. Thanks a lot.

p.s; some of you (very few) might remeber me making this project with a Neural AI. Well that's still in the making, only I have to get the whole basic game play down. Current project LOC: ~1,500

[Clayton]

INDENT YOUR CODE!!

other than that, I'm guessing that your objects are not being initialized before that loop, in which case your pointers are indeed NULL.

[PaulButler]

The Cards aren't being constructed. It looks like you are relying on this code:

Java:

Card [] handCards = new Card[4]; //Array to hold the four cards

to create the cards, but it does not call the constructors on each card, it gives each card a null value until you construct it. This should fix it:

Java:

for (int c = 0; c < 4; c++){ //Loops through the handCards array. /* The following line is what I added */ handCards[c] = new Card(); isDuplicate = true; while(isDuplicate){ //Loops through each card until a non-duplicate is selected if ( gameTable.checkDuplicate( handCards[c] ) ){ //Checks to see if the card generated has already been drawn handCards[c].regenerateValues(); } else {

Edit: Clayton beat me to it.

[Cinjection]

Clayton @ Sun Apr 08, 2007 1:07 pm wrote:

INDENT YOUR CODE!!

other than that, I'm guessing that your objects are not being initialized before that loop, in which case your pointers are indeed NULL.

1.Code was indented but i copy and pasted to post from a different forum so indenting got fucked.

2. So I can't create objects like that. I have to loop? Well that's cool. Thanks a lot fellers!