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I made a simple java program to create an array of cards (a deck), and then search a particular card within it [duplicate]

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Here, "cards" is the array of objects, and tcard (a jack of Diamonds), which should exist in the array, is the card I need to search. However the function always returns a value of -1.
public class Card
{
private int rank;
private int suit;
public static Card[] cards;
public Card(int rank, int suit)
{
this.rank = rank;
this.suit = suit;
}
public String toString() {
String[] ranks = {null, "Ace", "2", "3", "4", "5", "6",
"7", "8", "9", "10", "Jack", "Queen", "King"};
String[] suits = {"Clubs", "Diamonds", "Hearts", "Spades"};
String s = ranks[this.rank] + " of " + suits[this.suit];
return s;
}
public static void createDeck()
{
cards=new Card[52];
int in1=0;
for (int s1 = 0; s1<= 3; s1++) {
for (int r1 = 1; r1<= 13; r1++) {
cards[in1] = new Card(r1, s1);
in1++;
}
}
}
public static int search(Card[] scards, Card target) {
for (int i = 0; i < scards.length; i++) {
if (scards[i].equals(target)) {
return i;
}
}
return -1;
}
public static void main(String args[])
{
createDeck();
Card tcard=new Card(11,1);
int n1=search(cards,tcard);
System.out.println(n1);
}
}

Deck of cards index/array error

I'm trying to create a deck of cards that shuffles itself and then outputs the cards in random order. I am running into the error ArrayIndexOutOfBoundsException for the lines
return ranks[rank] + " of " + suits[suit];
and
System.out.println( C.toString() );
What am I doing wrong? It outputs the deck size, and then occasionally outputs a card or two before showing the error code. Thanks in advance.
import java.util.Random;
import java.util.ArrayList;
public class Deck
{
private ArrayList<Card> cards;
Deck()
{
cards = new ArrayList<Card>();
for (int a=0; a<=3; a++)
{
for (int b=0; b<=12; b++)
{
cards.add( new Card(a,b) );
}
}
}
public static void main(String[] args)
{
Deck deck = new Deck();
Card C;
System.out.println( deck.getTotalCards() );
while (deck.getTotalCards() != 0)
{
C = deck.drawFromDeck();
System.out.println( C.toString() );
}
}
public class Card
{
private int rank,
suit;
private String[] suits = {"Hearts", "Spades", "Diamonds", "Clubs"};
private String[] ranks = {"Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King"};
Card(int rank, int suit)
{
this.rank=rank;
this.suit=suit;
}
public #Override String toString()
{
return ranks[rank] + " of " + suits[suit];
}
public int getRank()
{
return rank;
}
public int getSuit()
{
return suit;
}
}
public Card drawFromDeck()
{
Random generator = new Random();
int index = generator.nextInt( cards.size() );
return cards.remove(index);
}
public int getTotalCards()
{
return cards.size();
}
}

Everything there is good but you initialize the cards backwards.
Your Card constructor is (rank, suit) and your Deck constructor is creating them (suit, rank).
Just flip the order of the args in your Deck constructor on line 15
cards.add( new Card(a, b) );
should be
cards.add( new Card(b, a) );
Since a ranges from 0 to 3, a is the suit, and should be the second argument in the constructor.

Card Class java

I am making a card and deck class that make a deck of 52 cards and the cardProgram class is the driver.The Card class has a property for the card's suit and a property for the value (Ace, King,10,9, etc). It also has a constructor for the properties and a toString representation for the card. The deck class ahs a property to represent cards in the deck and a constructor wit no parameters that will create 52 cards and add them to the deck, a method to randomly remove a card and return the card object that was drawn, and a toString to show the cards contained in the deck. Tha main will create the deck of cards. The user enters the number they would like to draw. Each card they draw is printed and then the cards remaining in the deck will be printed. I am using ArrayList to do this and I would just like to know if I am going in the right direction. I keep getting errors and I know there is something wrong in my classes. I have never used ArrayList before so any information would be appreciated
public class Card
{
private int type, value;
private String[] cardType = {"Clubs", "Spades", "Diamonds", "Hearts"};
private String[] cardValue = {"Ace", "King", "Queen", "Jack", "10",
"9", "8", "7", "6", "5", "4", "3", "2"};
public Card(int types, int values)
{
type = types;
value = values;
//this.value = value;
}
public String toString()
{
String finalCard = cardValue[value] + " of " + cardType[type];
return finalCard;
}
}
import java.util.Random;
import java.util.ArrayList;
public class Deck
{
private ArrayList<Card> cards;
public Deck()
{
for(int a =0; a<=3; a++)
{
for(int b =0; b<=12;b++)
{
cards.add(drawRandomCard());
}
cards.addAll(cards);
}
}
public Card drawRandomCard()
{
Random generator = new Random();
int index = generator.nextInt(cards.size());
return cards.remove(index);
}
public String toString()
{
String result = "Cards remaining in deck: " + cards;
return result;
}
}
import java.util.Scanner;
public class CardProgram
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
Card C;
Deck deck = new Deck();
System.out.println("Enter number of cards to be dealt: ");
int numberCards = scan.nextInt();
System.out.println("Cards drawn: ");
C = deck.drawRandomCard();
System.out.println(C.toString());
}
}

In terms of design guidelines there a couple things I would suggest:
1) Keep your local variables lower case (Card c)
2) Think about creating Java Enum for both rank and suit.
Your deck creation for loops would then look something like this:
cards = new ArrayList<Cards>();
for(Rank k : Rank.values())
for(Suit s: Suit.values())
cards.add(new Card(k,s));
3) An error you will get is probably an ArrayOutOfBoundsException since your Deck constructor is calling drawRandomCards() when initially cards is empty. Good Luck!
4) As was pointed out, you also haven't initialized cards yet.

Looking at your code, I think you are getting NullPointerException as you are talking about error.
You have defined private ArrayList<Card> cards; but you never initialized it in your Deck Class.
It should go something like
private ArrayList<Card> cards; // currently its null
cards = new ArrayList<Card>(); // initializing here and no more null

I think this is what you need. So what have I changed?
1.
When you initialised the deck, you need to populate the ArrayList with a card for each number combination. This is achieved by cards.add(new Card(a,b));. I've also removed the cards.addAll(cards) because you were adding the whole list to itself.
edit: oh yeh, and I initialised the ArrayList as well. That bits kind of important!
2.
In your CardProgram, you got the number of cards you wanted to draw, so I looped that many times calling, drawRandomCard().
3.
I haven't printed the remaining cards, that's up to you to figure out.
public class Card
{
private int type, value;
private String[] cardType = {"Clubs", "Spades", "Diamonds", "Hearts"};
private String[] cardValue = {"Ace", "King", "Queen", "Jack", "10",
"9", "8", "7", "6", "5", "4", "3", "2"};
public Card(int types, int values)
{
type = types;
value = values;
//this.value = value;
}
public String toString()
{
String finalCard = cardValue[value] + " of " + cardType[type];
return finalCard;
}
}
import java.util.Random;
import java.util.ArrayList;
public class Deck
{
private ArrayList<Card> cards;
public Deck()
{
cards = new ArrayList(52);
for(int a =0; a<=3; a++)
{
for(int b =0; b<=12;b++)
{
cards.add(new Card(a,b));
}
}
}
public Card drawRandomCard()
{
Random generator = new Random();
int index = generator.nextInt(cards.size());
return cards.remove(index);
}
public String toString()
{
String result = "Cards remaining in deck: " + cards;
return result;
}
}
import java.util.Scanner;
public class CardProgram
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
Card C;
Deck deck = new Deck();
System.out.println("Enter number of cards to be dealt: ");
int numberCards = scan.nextInt();
System.out.println("Cards drawn: ");
for (int i = 0; i < numberCards; i++) {
C = deck.drawRandomCard();
System.out.println(C.toString());
}
System.out.println(C.toString());
}
}

java simulation of a card dealer - ArrayIndexOutOfBoundsException

I am having trouble executing my code and unable to pinpoint exactly the source of the error or why and maybe someone might be able to take a look and provide me with some feedback if possible.
Error message:
51
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1
3 of Clubs, Diamonds, Hearts, Spades
at javacards.Card.toString(Card.java:15)
at javacards.CardRun.main(CardRun.java:15)
CardRun Class:
public class CardRun {
public static void main(String[] args)
{
Deck deck = new Deck();
Card C;
System.out.println(deck.getTotalCards());
while(deck.getTotalCards() != 0)
{
C = deck.drawFromDeck();
System.out.println(C.toString());
}
}
Card Class
public class Card {
private int card, suit;
private static String[] suits = {"Clubs, Diamonds, Hearts, Spades"};
private static String[] cards = {"Ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King"};
Card(int suit, int card)
{
this.card = card;
this.suit = suit;
}
public #Override String toString()
{
return cards[card] + " of " + suits[suit];
}
public int getCard()
{
return card;
}
public int getSuit()
{
return suit;
}
}
Deck Class
public class Deck {
private Card[]cards;
int i;
Deck()
{
i = 51;
cards = new Card[52];
int x = 0;
for(int a=0; a<=3; a++)
{
for(int b=0; b<=12; b++)
{
cards[x] = new Card(a,b);
x++;
}
}
}
public Card drawFromDeck()
{
Random generator = new Random();
int index = 0;
index = generator.nextInt(i);
Card temp = cards[index];
cards[index] = cards[i];
cards[i] = null;
i--;
return temp;
}
public int getTotalCards()
{
return i;
}
}

This array:
private static String[] suits = {"Clubs, Diamonds, Hearts, Spades"};
only contains one item - you probably meant:
private static String[] suits = {"Clubs", "Diamonds", "Hearts", "Spades"};

How to deal 4 hands of 10 cards with a deck?

So I have the code for a deck, but I dont know how to make another class to deal 4 hands of 10 cards each. The other class should print on the screen, in text, 4 hands of 10 random cards. Can someone show me the code on how to accomplish this? Im using blueJ aswell.
Below is my code for the deck:
public class Card
{
public static void main(String[] args)
{
String[] suit = { "Clubs", "Diamonds", "Hearts", "Spades" };
String[] rank = { "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King", "Ace" };
int SUITS = suit.length;
int RANKS = rank.length;
int N = SUITS * RANKS;
// initialize deck
String[] deck = new String[N];
for (int i = 0; i < RANKS; i++) {
for (int j = 0; j < SUITS; j++) {
deck[SUITS*i + j] = rank[i] + " of " + suit[j];
}
}
// shuffle the deck
for (int i = 0; i < N; i++) {
int r = i + (int) (Math.random() * (N-i));
String t = deck[r];
deck[r] = deck[i];
deck[i] = t;
}
for (int i = 0; i < N; i++) {
System.out.println(deck[i]);
}
}
}

In the spirit of the game, let's create a hierarchy for handling could work. The largest scope will be the Game, which will delegate the actions to the other classes. We will also have 3 classes: Deck, Dealer, Player.
A Game will have a Dealer, and an ArrayList of Player
A Dealer will have a Deck
A Player will have an ArrayList of String indicating your cards
A Game can then tell a dealer to create and shuffle a deck. You can call a dealCards passing the Players as a param to the dealer who can, based on the number of players, give them the next element in the Deck, and remove that element from the deck.
Once you have dealt all the cards, the game can then tell the players to show their hands, printing the results.
public Dealer{
private Deck deck;
....
public void shuffleDeck(){...}
public void dealCards(List<Player> players){ ...}
}
public Player{
private List<String> hand;
....
public void addToHand(String card){....}
}

Your Card / Deck class should be broken up into two classes.
A Card class would describe a card.
public class Card {
private String rank;
private String suit;
public Card(String rank, String suit) {
this.rank = rank;
this.suit = suit;
}
public String getRank() {
return rank;
}
public String getSuit() {
return suit;
}
#Override
public String toString() {
return rank + " of " + suit;
}
}
A Deck class describes a deck of cards.
public class Deck {
private String[] rank = { "2", "3", "4", "5", "6", "7", "8", "9",
"10", "Jack", "Queen", "King", "Ace" };
private String[] suit = { "Clubs", "Diamonds", "Hearts", "Spades" };
private Card[] cards;
public Deck() {
cards = new Card[suit.length * rank.length];
for (int i = 0; i < rank.length; i++) {
for (int j = 0; j < suit.length; j++) {
cards[suit.length * i + j] = new Card(rank[i], suit[j]);
}
}
}
public Card[] shuffleDeck() {
for (int i = 0; i < cards.length; i++) {
int r = (int) (Math.random() * (cards.length - 1));
Card t = cards[r];
cards[r] = cards[i];
cards[i] = t;
}
return cards;
}
#Override
public String toString() {
StringBuilder builder = new StringBuilder();
for (int i = 0; i < cards.length; i++) {
builder.append(cards[i].toString());
builder.append(System.getProperty("line.separator"));
}
return builder.toString();
}
}
Until you understand how these two classes work together, there's no point introducing other classes.
The point of Java, or any object oriented computer language, is to break up your problem into smaller classes that each do one thing and do it well.