我正在开发一个涉及Card对象和Deck对象的Java项目.当我制作Deck时,我有一个ArrayList,其中包含所有52张卡片.但是,当我在Collections中使用shuffle方法时,四个Card对象变为null.Card类工作正常,当我在shuffle方法之前打印出Deck时,所有52张卡都在那里.一旦我在甲板上洗牌,那就是我得到四个空方法的时候.
import java.util.ArrayList;
import java.util.Collections;
public class Deck {
public ArrayList<Card> pack = new ArrayList<Card>();
public int spades = 1;
public int hearts = 1;
public int diamonds = 1;
public int clubs = 1;
public String s = "spades";
public String h = "hearts";
public String cl = "clubs";
public String d = "diamonds";
public Deck(){
}
public void makeDeck()
{
for (int i = 0; i < 14; i++)
{
Card c = null;
if (clubs < 14) …