我遇到了一个令人头疼的问题,我知道出了什么问题,但无法将其放入代码中。我目前正在制作一套卡片组,我想从 LinkedHashMap
中的卡片等级中删除特定的卡片套装。 。我已经到处搜索针对我的具体问题的具体解决方案,但无法找到。
我尝试过使用 EntrySet、迭代器和逻辑解决方案,但是 remove()
操作好像删除了value
的所有记录忽略key
。
下面的示例演示了我尝试删除 5 颗红心的尝试。
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
public class Main {
public static void main(String[] args) {
Deck deck = new Deck();
System.out.println(deck.deck);
//ENTRYSET
for (Map.Entry<String, LinkedList<String>> entry : deck.deck.entrySet()) {
System.out.println(entry.getValue());
System.out.println(entry.getKey());
if (entry.getKey().contains("5")) {
if (entry.getValue().contains("Hearts")) {
entry.getValue().remove("Hearts");
break;
}
}
}
System.out.println(deck.deck);
//LOGIC SOLUTION
if (! deck.deck.get("5").isEmpty()) {
deck.deck.get("King").remove("Hearts");
}
//ITERATOR
for (Iterator<Map.Entry<String, LinkedList<String>>> it = deck.deck.entrySet().iterator(); it.hasNext(); ) {
Map.Entry<String, LinkedList<String>> entry = it.next();
LinkedList<String> list = entry.getValue();
System.out.println(list);
if (entry.getKey().equals("5")) {
for (int i = 0; i < list.size(); i++) {
if (list.get(i).equals("Hearts")) {
list.remove(i);
break;
}
}
if (list.isEmpty())
it.remove();
}
}
System.out.println(deck.deck);
}
}
输出条目集:
{2=[Clubs, Diamonds, Hearts, Spades], 3=[Clubs, Diamonds, Hearts, Spades], 4=[Clubs, Diamonds, Hearts, Spades], 5=[Clubs, Diamonds, Hearts, Spades], 6=[Clubs, Diamonds, Hearts, Spades], 7=[Clubs, Diamonds, Hearts, Spades], 8=[Clubs, Diamonds, Hearts, Spades], 9=[Clubs, Diamonds, Hearts, Spades], 10=[Clubs, Diamonds, Hearts, Spades], Jack=[Clubs, Diamonds, Hearts, Spades], Queen=[Clubs, Diamonds, Hearts, Spades], King=[Clubs, Diamonds, Hearts, Spades], Ace=[Clubs, Diamonds, Hearts, Spades]}
[Clubs, Diamonds, Hearts, Spades]
2
[Clubs, Diamonds, Hearts, Spades]
3
[Clubs, Diamonds, Hearts, Spades]
4
[Clubs, Diamonds, Hearts, Spades]
5
{2=[Clubs, Diamonds, Spades], 3=[Clubs, Diamonds, Spades], 4=[Clubs, Diamonds, Spades], 5=[Clubs, Diamonds, Spades], 6=[Clubs, Diamonds, Spades], 7=[Clubs, Diamonds, Spades], 8=[Clubs, Diamonds, Spades], 9=[Clubs, Diamonds, Spades], 10=[Clubs, Diamonds, Spades], Jack=[Clubs, Diamonds, Spades], Queen=[Clubs, Diamonds, Spades], King=[Clubs, Diamonds, Spades], Ace=[Clubs, Diamonds, Spades]}
输出逻辑解决方案:
{2=[Clubs, Diamonds, Hearts, Spades], 3=[Clubs, Diamonds, Hearts, Spades], 4=[Clubs, Diamonds, Hearts, Spades], 5=[Clubs, Diamonds, Hearts, Spades], 6=[Clubs, Diamonds, Hearts, Spades], 7=[Clubs, Diamonds, Hearts, Spades], 8=[Clubs, Diamonds, Hearts, Spades], 9=[Clubs, Diamonds, Hearts, Spades], 10=[Clubs, Diamonds, Hearts, Spades], Jack=[Clubs, Diamonds, Hearts, Spades], Queen=[Clubs, Diamonds, Hearts, Spades], King=[Clubs, Diamonds, Hearts, Spades], Ace=[Clubs, Diamonds, Hearts, Spades]}
{2=[Clubs, Diamonds, Spades], 3=[Clubs, Diamonds, Spades], 4=[Clubs, Diamonds, Spades], 5=[Clubs, Diamonds, Spades], 6=[Clubs, Diamonds, Spades], 7=[Clubs, Diamonds, Spades], 8=[Clubs, Diamonds, Spades], 9=[Clubs, Diamonds, Spades], 10=[Clubs, Diamonds, Spades], Jack=[Clubs, Diamonds, Spades], Queen=[Clubs, Diamonds, Spades], King=[Clubs, Diamonds, Spades], Ace=[Clubs, Diamonds, Spades]}
输出迭代器:
{2=[Clubs, Diamonds, Hearts, Spades], 3=[Clubs, Diamonds, Hearts, Spades], 4=[Clubs, Diamonds, Hearts, Spades], 5=[Clubs, Diamonds, Hearts, Spades], 6=[Clubs, Diamonds, Hearts, Spades], 7=[Clubs, Diamonds, Hearts, Spades], 8=[Clubs, Diamonds, Hearts, Spades], 9=[Clubs, Diamonds, Hearts, Spades], 10=[Clubs, Diamonds, Hearts, Spades], Jack=[Clubs, Diamonds, Hearts, Spades], Queen=[Clubs, Diamonds, Hearts, Spades], King=[Clubs, Diamonds, Hearts, Spades], Ace=[Clubs, Diamonds, Hearts, Spades]}
[Clubs, Diamonds, Hearts, Spades]
[Clubs, Diamonds, Hearts, Spades]
[Clubs, Diamonds, Hearts, Spades]
[Clubs, Diamonds, Hearts, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
[Clubs, Diamonds, Spades]
{2=[Clubs, Diamonds, Spades], 3=[Clubs, Diamonds, Spades], 4=[Clubs, Diamonds, Spades], 5=[Clubs, Diamonds, Spades], 6=[Clubs, Diamonds, Spades], 7=[Clubs, Diamonds, Spades], 8=[Clubs, Diamonds, Spades], 9=[Clubs, Diamonds, Spades], 10=[Clubs, Diamonds, Spades], Jack=[Clubs, Diamonds, Spades], Queen=[Clubs, Diamonds, Spades], King=[Clubs, Diamonds, Spades], Ace=[Clubs, Diamonds, Spades]}
我希望 map 包含什么内容:
{2=[Clubs, Diamonds, Hearts, Spades], 3=[Clubs, Diamonds, Hearts, Spades], 4=[Clubs, Diamonds, Hearts, Spades], 5=[Clubs, Diamonds, Spades], 6=[Clubs, Diamonds, Hearts, Spades], 7=[Clubs, Diamonds, Hearts, Spades], 8=[Clubs, Diamonds, Hearts, Spades], 9=[Clubs, Diamonds, Hearts, Spades], 10=[Clubs, Diamonds, Hearts, Spades], Jack=[Clubs, Diamonds, Hearts, Spades], Queen=[Clubs, Diamonds, Hearts, Spades], King=[Clubs, Diamonds, Hearts, Spades], Ace=[Clubs, Diamonds, Hearts, Spades]}
那么我该如何指定移除套装的 key 呢?我不希望删除“Hearts”的所有实例(如本例所示)。非常感谢帮助和线索!
编辑:
套装的数量使得关键点仅指向 map 内存中的一个列表。
之前:
public Deck() {
for (int i = 2; i <= 10; i++) {
deck.put(String.valueOf(i), suits));
}
for (int i = 0; i <= 3; i++) {
deck.put(highRank.get(i), suits));
}
}
之后:
public Deck() {
for (int i = 2; i <= 10; i++) {
deck.put(String.valueOf(i), new LinkedList<String>(Arrays.asList("Clubs", "Diamonds", "Hearts", "Spades")));
}
for (int i = 0; i <= 3; i++) {
deck.put(highRank.get(i), new LinkedList<String>(Arrays.asList("Clubs", "Diamonds", "Hearts", "Spades")));
}
}
最佳答案
问题出在 map 人口上,而不是删除时:
如果您有以下情况:
Map<String, List> myMap = ...
List<String> myList = ...
myMap.put("1", myList);
myMap.put("2", myList);
然后,当您删除时,您将同时从两个 map 条目中删除:
myMap.get("1").remove("Hearts"); // removes both from myMap.get("1") and MyMap.get("2")
关于java - 从 LinkedHashMap 中删除包含键 <String> 和值 LinkedList<String> 的特定值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53491333/