从HashMap的双端队列获取密钥 [英] Getting the key from a Deque of a HashMap

问题描述

我有一个这样的双端队列:

I have a deque that looks like this:

@Getter
private Deque<Map<int, String>> cars = new LinkedList<>();

我只想用钥匙从地图双端队列中移除每辆车.像这样:

I want to remove each car from the deque of the map using only the key. So something like this:

getCars().stream().forEach(car -> delete(car.keySet().iterator().next()));

是否有更好的方法来处理此问题，而不必使用interator().next()?

Is there a better way to handle this, instead of having to use interator().next()?

推荐答案

The removeIf method should do the trick:

int keyToDelete = 7; // Arbitrary number
cars.removeIf(m -> m.containsKey(keyToDelete));

在早期的Java版本中，相同的功能也是可能的，尽管语法会更笨拙-您必须获取列表的迭代器，然后遍历它，评估每个项目:

In earlier Java versions the same functionality is also possible, although the syntax would be clunkier - you'll have to get an iterator of the list, and go over it, evaluating every item:

int keyToDelete = 7; // Arbitrary number
Iterator<Map<Integer, String>> iter = cars.iterator();

while(iter.hasNext()) {
    Map<Integer, String> map = iter.next();
    if (map.containsKey(keyToDelete)) {
        iter.remove();
    }
}

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