Bluej ArrayList添加

Question

我试着做一个纸牌游戏，我的卡片类和我的甲板类准备好了，它编译好了，但是当我尝试运行makeDeckFull方法时，我得到了输出:失效编号

当我使用showDeck方法时，我看到的不是“心脏”，而是1 Cards@597f13c5 (我不知道它意味着什么，也不知道如何修复它)

任何帮助都将不胜感激:代码如下。

甲板级：

import java.util.ArrayList;
public class Deck
{
    private ArrayList<Cards> deck;
    private int index;

    public Deck()
    {
        deck = new ArrayList<Cards>();
    }

    public void makeDeckFull()
    {
        Cards h1 = new Cards("Hearts", 1);
        Cards h2 = new Cards("Hearts", 2);
        Cards h3 = new Cards("Hearts", 3);
        deck.add(h1);
        index ++;
        deck.add(h2);
        index ++;
        deck.add(h3);
        index ++;
        //Rest of these is left out to conserve space
    }

    public void showDeck()
    {
        System.out.println(deck); 
    }

卡片类：

public class Cards
{
    private String HEARTS = "Hearts";
    private String CLUBS = "Clubs";
    private String DIAMONDS = "Diamonds";
    private String SPADES = "Spades";
    public int number;
    public String suit;
    public Cards()
    {
        suit = "unknown suit";
        number = 0;
    }

    public Cards(String suit, int number)
    {
        setSuit(suit);
        setNumber(number);

    }

    public void setCard(String suit, int number2)
    {
        setSuit(suit);
        setNumber(number2);

    }
    public void setSuit(String newSuit)
    {
        if(
            (newSuit.equalsIgnoreCase(HEARTS)) ||
            (newSuit.equalsIgnoreCase(DIAMONDS)) ||
            (newSuit.equalsIgnoreCase(CLUBS))    ||
            (newSuit.equalsIgnoreCase(SPADES)))
        {
            suit = newSuit;
        }
        else 
        {
            newSuit = "invalid";
            System.out.print("Invalid");
        }        
    }
    public int getNumber()
    {
        return number;
    }
    public String getSuit()
    {
        return suit;
    }

    public void setNumber(int newNumber)
    {

        if(newNumber >0 && newNumber <=10)
        {
            number = newNumber;
        }
        else
        {
            number = 0;
            System.out.print("invalid number");
        }
    }
}

Answer 1

1)您需要在toString()类中重写Cards。实际上，您打印的是对象的引用(胡言乱语)，而不是“数据”。您还应该重写Deck的Deck方法，使其只打印出列表。

2)我正在逐步了解您的makeDeckFull()代码片段，它似乎运行得很好。您确定这三种插入都是获得无效打印语句的地方吗？