Java 将Arraylist中的对象替换为Arraylist中先前存在的另一个对象

我试图检测我的arraylist中两个对象（卡片）之间的两个特征中的一个是否相同，并用另一个替换其中一个对象

例如，ArrayList中的最后3个对象如下所示：

King of Diamonds
Ace of Clubs
Ace of Spades

梅花王牌和黑桃王牌之间的共同因素是王牌价值。在现实世界中，你会将黑桃王牌移动到梅花王牌上，在比赛中再也不会显示梅花王牌

就ArrayList而言，这可以通过在ArrayList中的位置用黑桃王牌替换梅花王牌，并完全删除梅花王牌，使ArrayList的大小为51（52张牌减去我们刚才删除的那张牌）来实现

对于某些上下文，下面是Card类的外观，它包含每张卡的特征：

package uk.ac.aber.dcs.cs12320.cards;

import java.util.ArrayList;


public class Card {

protected String value;
protected String suit;
 ArrayList<Card> cardsList = new ArrayList<>();

public Card(String v, String s){
    this.value = v;
    this.suit = s;
}

public Card() {

}

public  Card[] getAll(){
    Card[] brb = new Card[cardsList.size()];
    int tempCount = -1;
    for(Card c : cardsList){
        tempCount++;
        brb[tempCount] = c;
    }
    return brb;
}

public  void deleteAll(){
    cardsList.clear();
}

public  String getValue() {
    return value;
}

public void setValue(String value) {
    this.value = value;
}

public  String getSuit() {
    return suit;
}

public void setSuit(String suit) {
    this.suit = suit;
}

public void addCard(Card card){
    cardsList.add(card);
}

}

    private void dealCard(){
    //TODO
    int totalLeftOver = 0; // used to count the cards left in the shuffled-but-not-dealt pack
    Card topCard = shuffledPack.get(0);
    shuffledPack.remove(0);
    theFlop.add(topCard);
    System.out.print("Cards on the flop: ");
    for(Card dealt : theFlop){
        String definitelyDealt = dealt.getValue() + dealt.getSuit() + " ";
        System.out.print(definitelyDealt);
    }
    System.out.println("\n");
    for(Card card : shuffledPack){ // for loop to count how cards haven't been dealt
        totalLeftOver++;
    }
    System.out.println("Total number of cards left to deal: " + totalLeftOver); // show how many cards haven't been dealt to the player
}

    private void makeMovePreviousPile(){
    int lastDealtCardPos = theFlop.size() - 1; //allows us to see how many cards have been dealt, are you even trying to challenge us Chris?
    int previouslyDealtCardPos = lastDealtCardPos - 1;

    if(lastDealtCardPos != 0){ // check that the deck has been shuffled and at least 1 card has been dealt.

        String lastDealtCardValue = theFlop.get(lastDealtCardPos).getValue(); // fetches the value of the last dealt card
        String lastDealtCardSuit = theFlop.get(lastDealtCardPos).getSuit(); // fetches the suit of the last dealt card
        String previouslyDealtCardValue = theFlop.get(previouslyDealtCardPos).getValue(); // fetches the 2nd to last dealt card's value
        String previouslyDealtCardSuit = theFlop.get(previouslyDealtCardPos).getSuit(); // fetches the 2nd to last dealt card's suit

        if(lastDealtCardValue.equals(previouslyDealtCardValue)){
            theFlop.remove(previouslyDealtCardPos);
        }
        else if(lastDealtCardSuit.equals(previouslyDealtCardSuit)) {
            theFlop.remove(previouslyDealtCardPos);
        }
        else {
            System.out.println("Cannot make a move. Are you sure you know the rules?");
        }
        System.out.println("\n");
        printCardsFromFlop();
    }
    else { // if it hasn't been shuffled we shun the user.
        System.out.println("Are you sure you shuffled the deck and dealt a card before trying to make a move?");
    }
    System.out.print("Total cards on the flop: " + lastDealtCardPos + "\n"); // checking to see that its working as intended
}

如果先前发过的一张牌有匹配的值（套牌或值），我可以使用以下方法移除一张牌：

package uk.ac.aber.dcs.cs12320.cards;

import java.util.ArrayList;


public class Card {

protected String value;
protected String suit;
 ArrayList<Card> cardsList = new ArrayList<>();

public Card(String v, String s){
    this.value = v;
    this.suit = s;
}

public Card() {

}

public  Card[] getAll(){
    Card[] brb = new Card[cardsList.size()];
    int tempCount = -1;
    for(Card c : cardsList){
        tempCount++;
        brb[tempCount] = c;
    }
    return brb;
}

public  void deleteAll(){
    cardsList.clear();
}

public  String getValue() {
    return value;
}

public void setValue(String value) {
    this.value = value;
}

public  String getSuit() {
    return suit;
}

public void setSuit(String suit) {
    this.suit = suit;
}

public void addCard(Card card){
    cardsList.add(card);
}

}

    private void dealCard(){
    //TODO
    int totalLeftOver = 0; // used to count the cards left in the shuffled-but-not-dealt pack
    Card topCard = shuffledPack.get(0);
    shuffledPack.remove(0);
    theFlop.add(topCard);
    System.out.print("Cards on the flop: ");
    for(Card dealt : theFlop){
        String definitelyDealt = dealt.getValue() + dealt.getSuit() + " ";
        System.out.print(definitelyDealt);
    }
    System.out.println("\n");
    for(Card card : shuffledPack){ // for loop to count how cards haven't been dealt
        totalLeftOver++;
    }
    System.out.println("Total number of cards left to deal: " + totalLeftOver); // show how many cards haven't been dealt to the player
}

    private void makeMovePreviousPile(){
    int lastDealtCardPos = theFlop.size() - 1; //allows us to see how many cards have been dealt, are you even trying to challenge us Chris?
    int previouslyDealtCardPos = lastDealtCardPos - 1;

    if(lastDealtCardPos != 0){ // check that the deck has been shuffled and at least 1 card has been dealt.

        String lastDealtCardValue = theFlop.get(lastDealtCardPos).getValue(); // fetches the value of the last dealt card
        String lastDealtCardSuit = theFlop.get(lastDealtCardPos).getSuit(); // fetches the suit of the last dealt card
        String previouslyDealtCardValue = theFlop.get(previouslyDealtCardPos).getValue(); // fetches the 2nd to last dealt card's value
        String previouslyDealtCardSuit = theFlop.get(previouslyDealtCardPos).getSuit(); // fetches the 2nd to last dealt card's suit

        if(lastDealtCardValue.equals(previouslyDealtCardValue)){
            theFlop.remove(previouslyDealtCardPos);
        }
        else if(lastDealtCardSuit.equals(previouslyDealtCardSuit)) {
            theFlop.remove(previouslyDealtCardPos);
        }
        else {
            System.out.println("Cannot make a move. Are you sure you know the rules?");
        }
        System.out.println("\n");
        printCardsFromFlop();
    }
    else { // if it hasn't been shuffled we shun the user.
        System.out.println("Are you sure you shuffled the deck and dealt a card before trying to make a move?");
    }
    System.out.print("Total cards on the flop: " + lastDealtCardPos + "\n"); // checking to see that its working as intended
}

上述方法检测两个值中的一个是否匹配，然后从arraylist中移除先前发牌的牌，最近发牌的牌在arraylist中占据其位置（就现实生活中的棋盘本身而言，最近发牌的牌位于先前发牌的牌之上，在游戏的其余部分将其隐藏）

我试图做的与上面的移除方法类似。如果满足两个特征中的一个，我希望将发了2次的卡替换回原来的卡。假设arraylist现在看起来像这样，我们必须将对象（2）替换为对象（0）：

假设发了3张牌，我如何用位置2的对象替换位置0的对象？更好的方法：

Collections.swap(list, list.indexOf(firstCardToBeReplaced), list.indexOf(secondCardToBeReplaced));

或者可以使用ArrayList中的方法“set（int-index，E-element）”

int firstPosition = list.indexOf(firstCardToBeReplaced);
int secondPosition = list.indexOf(secondCardToBeReplaced);
list.set(firstPosition, secondCardToBeReplaced);
list.set(secondPosition, firstCardToBeReplaced);

---

它将在对象的位置替换为新元素。

根据您的问题，下面的代码使用0和2的硬索引。由您决定如何防止出现异常

这样替换

cardsList.set(0, cardsList.get(2));

如果要删除2个，请使用这两个

cardsList.remove(2);

---

谢谢，我已经输入了以下内容：

theFlop.set（theFlop.indexOf（TwoCardsBackDealtPos），lastDealtCardPosition）；

这给了我一个错误：

类型ArrayList中的方法集（int，Card）不适用于参数（int，int）

，您能简单地解释一下为什么会发生这种情况，以便我能找到解决方案吗？您必须将要替换的对象放在第二个参数上。我编辑了我的代码，我认为这会更容易理解。这样会将ArrayList中位置2的对象移动到位置0吗？还是会将对象0向上推到位置0位置1，然后将对象（2）设置为位置0？如果有意义的话。它会将位置0处的对象替换为位置2处的对象。这是您想要的吗？也可以添加到其他asnwer中的注释中。请尝试

offlop.set（offlop.indexOf（TwoCardsBackDealtPos），offlop.get（lastDealtCardPosition））

经过尝试和测试，效果非常好。没有删除，它只是替换了值，但将现有值保留在位置2，添加删除将其从数组中删除。非常感谢，将您的答案标记为正确。干杯！