java - 一副牌

Question

我是一个尝试学习 Java 的新手，但在完成给自己的任务时遇到了一些困难。基本上我正在尝试做本文末尾的练习page.

我成功地完成了三节课。 卡片:

public class Card {

public int nRank; // Used later
public int maxRank = 13; //The max number of Ranks
public int nSuit; // Used later
public int maxSuit = 4; // Max number of suits


//Associate both rank and suit numbers with strings

public String[] ranks = new String[maxRank - 1];
{
    ranks[0] = "two";
    ranks[1] = "three";
    ranks[2] = "four";
    ranks[3] = "five";
    ranks[4] = "six";
    ranks[5] = "seven";
    ranks[6] = "eight";
    ranks[7] = "nine";
    ranks[8] = "ten";
    ranks[9] = "Jack";
    ranks[10] = "Queen";
    ranks[11] = "King";
    ranks[12] = "Ace";

    }

public String[] suits = new String[maxSuit - 1];
{
    suits[0] = "Clubs";
    suits[1] = "Diamonds";
    suits[2] = "Spades";
    suits[3] = "Hearts";
    }

public String suit = suits[nSuit]; //The suit string of the card whose suit number is nSuit
public String rank = ranks[nRank]; //Same but with ranks

//Constructor for the Card object, with two arguments, x for rank, y for suit
public Card(int x,int y){
    this.nRank = x;
    this.nSuit = y;
}

//method to get which card it is in a string
public String whatCard(){
    return rank + " of " + suit;
}
}

套牌:

    public class Deck {

public static int nRanks = 13; //number of ranks
public static int nSuits = 4; // number of suits
public static int nCard = nRanks * nSuits; // number of cards

Card[] deck = new Card[nCard -1]; //new array called deck to store all the cards 
int h = 0; //a variable to control the place of each card in the array
//constructor for the Deck
public Deck() {

while(h < 52){ // loop until there are 52 cards

// cycles through all the possible combinations between i(ranks) and j(suits) and creates a card with each
for(int i = 1; i <= nRanks; i++){

    for(int j = 1; j <= nSuits; j++){

        deck[h] = new Card(i,j); // creation of the card
        h++; // adds 1 to to h so the program knows how many cards are there
        }
    }

}
}
//method for getting a card depending on its position in the array(x)
    public Card getCard(int x){
    return deck[x-1];   
}
}

还有牌/牌组的显示，我称之为随机播放:

public class Shuffle {

public static void main(String[] args){
        Deck newDeck = new Deck(); // creates a new Deck object
        //loops through all the cards in the deck
    for(int i = 0; i < Deck.nCard; i++){
        System.out.println(newDeck.getCard(i).whatCard()); // prints each card
    }

}

}

虽然 Eclipse 没有注意到代码中的任何错误，但当我尝试编译时，我会看到以下内容:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 12
    at Card.<init>(Card.java:26)
    at Deck.<init>(Deck.java:20)
    at Shuffle.main(Shuffle.java:5)

我错过了什么？

Answer 1

在所有长度为 N 的循环中，您尝试从元素 1..N 进行访问。您应该从 0..(1-N) 开始循环。

例如，如果您有 4 个花色，则您将拥有一个包含元素 0、1、2、3 的数组。通过说(for j=1; j<=4, j++) ，您正在尝试访问超出范围的元素 4。

它应该是 (j=0; j<4; j++) .