EDIT: My first Question was resolved, however, the function getValue() always returns 11. Any thoughts?
EDIT: Found it,
Collections.shuffle(Arrays.asList(deck));
Isn't properly shuffling. I don't know why.
I'm doing an assignment where I have to write/fill in some code to write a simple blackjack program.
There are three classes I have defined, a Card Class, a Hand Class (which is an array of Cards and some other values) and a Deck class which is also an array of Cards.
In the Hand class I have a method that adds up all the values of the cards, and whenever I run my code, I get a java.lang.NullPointerException, and the console points to my this "addHand" method:
public int addHand(){
int j=0;
for(int i=0; i<=counter-1; i++){
j += Cards[i].getValue();
}
return j;
}
I think it is because some of the values in Cards[] are null. But the "counter" should not let any of them get added. I'll include the rest of the Hand Class, as well as the Card Class.
Hand Class:
public class Hand {
private Card[] Cards;
private int counter;
//private int valueOfHand;
public Hand(){
Cards = new Card[10];
counter = 0;
}
public int numCards(){
return counter;
}
public Card getCard(int i){
return Cards[i];
}
public int getCounter() {
return counter;
}
public void setCounter(int counter) {
this.counter = counter;
}
public void addCard(Card card){
Cards[counter] = card;
setCounter(counter+1);
}
public int addHand(){
int j=0;
for(int i=0; i<=counter-1; i++){
j += Cards[i].getValue();
}
return j;
}
}
And the Card Class:
public class Card {
private String value;
private String suit;
public Card(String number, String shape){
value = number;
suit = shape;
}
public int getValue() {
if (value.equals("King") || value.equals("Queen") || value.equals("Jack")){
return 10;
}
else if (value.equals("Ace")){
return 11;
}
else {
return Integer.parseInt(value);
}
}
public void setValue(String value) {
this.value = value;
}
public String getSuit() {
return suit;
}
public void setSuit(String suit) {
this.suit = suit;
}
}
I don't know if I need to post anything else, I would be happy to if necessary.
The exact error is:
Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
at Hand.addHand(Hand.java:39)
at BlackJackGUIPanel$CardPanel.hitMe(BlackJackGUIPanel.java:182)
at BlackJackGUIPanel$CardPanel.actionPerformed(BlackJackGUIPanel.java:161)
Here is the Hitme code:
void hitMe() {
if (!gameInProgress) {
message = "Click \"New Game\" to start a new game!";
repaint();
return;
}
player.addCard(deck.giveCard());
if(player.addHand() > 21){
message = "Game over, you busted";
gameInProgress = false;
}
message = "You clicked Hit Me!";
repaint();
and the giveCard() code:
public Card giveCard(){
Card temp = Decks[0];
for(int i = 1; i<52; i++){
Decks[i-1] = Decks[i];
}
Decks[51] = temp;
return temp;
}
I couldn't find a better way to do this part. here is where I initialize my deck:
public Deck(){
Decks = new Card[52];
//int cardNumber = 2;
for(int i = 0; i < 52; i += 4){
switch (i/4){
case 0: Decks[i] = new Card("2", "Spades");
Decks[i+1] = new Card("2", "Hearts");
Decks[i+2] = new Card("2", "Clubs");
Decks[i+3] = new Card("2", "Diamonds");
case 4: Decks[i] = new Card("3", "Spades");
Decks[i+1] = new Card("3", "Hearts");
Decks[i+2] = new Card("3", "Clubs");
Decks[i+3] = new Card("3", "Diamonds");
case 8: Decks[i] = new Card("4", "Spades");
Decks[i+1] = new Card("4", "Hearts");
Decks[i+2] = new Card("4", "Clubs");
Decks[i+3] = new Card("4", "Diamonds");
case 12: Decks[i] = new Card("5", "Spades");
Decks[i+1] = new Card("5", "Hearts");
Decks[i+2] = new Card("5", "Clubs");
Decks[i+3] = new Card("5", "Diamonds");
case 16: Decks[i] = new Card("6", "Spades");
Decks[i+1] = new Card("6", "Hearts");
Decks[i+2] = new Card("6", "Clubs");
Decks[i+3] = new Card("6", "Diamonds");
case 20: Decks[i] = new Card("7", "Spades");
Decks[i+1] = new Card("7", "Hearts");
Decks[i+2] = new Card("7", "Clubs");
Decks[i+3] = new Card("7", "Diamonds");
case 24: Decks[i] = new Card("8", "Spades");
Decks[i+1] = new Card("8", "Hearts");
Decks[i+2] = new Card("8", "Clubs");
Decks[i+3] = new Card("8", "Diamonds");
case 28: Decks[i] = new Card("9", "Spades");
Decks[i+1] = new Card("9", "Hearts");
Decks[i+2] = new Card("9", "Clubs");
Decks[i+3] = new Card("9", "Diamonds");
case 32: Decks[i] = new Card("10", "Spades");
Decks[i+1] = new Card("10", "Hearts");
Decks[i+2] = new Card("10", "Clubs");
Decks[i+3] = new Card("10", "Diamonds");
case 36: Decks[i] = new Card("Jack", "Spades");
Decks[i+1] = new Card("Jack", "Hearts");
Decks[i+2] = new Card("Jack", "Clubs");
Decks[i+3] = new Card("Jack", "Diamonds");
case 40: Decks[i] = new Card("Queen", "Spades");
Decks[i+1] = new Card("Queen", "Hearts");
Decks[i+2] = new Card("Queen", "Clubs");
Decks[i+3] = new Card("Queen", "Diamonds");
case 44: Decks[i] = new Card("King", "Spades");
Decks[i+1] = new Card("King", "Hearts");
Decks[i+2] = new Card("King", "Clubs");
Decks[i+3] = new Card("King", "Diamonds");
case 48: Decks[i] = new Card("Ace", "Spades");
Decks[i+1] = new Card("Ace", "Hearts");
Decks[i+2] = new Card("Ace", "Clubs");
Decks[i+3] = new Card("Ace", "Diamonds");
}
}
Collections.shuffle(Arrays.asList(Decks));
}
As a debug you could do this
public int addHand()
{
int j=0;
for(int i=0; i<=counter-1; i++)
{
Card c = Cards[i];
if(c != null)
j += Cards[i].getValue();
else
System.out.println("Add hand was trying to add a null card for index = " + i);
}
return j;
}
You may also want to add a check to your addCard(Card) method so that null cards cannot be added
public void addCard(Card card)
{
if(card != null)
{
Cards[counter] = card;
setCounter(counter+1);
}
else
System.out.println("NO NO NO! Trying to add a null card to your hand");
}