LinkedList迭代器删除 [英] LinkedList iterator remove

问题描述

可能重复：

在迭代集合时删除元素的高效等价物

private LinkedList flights;

....

public void clear(){

    ListIterator itr = flights.listIterator();

    while(itr.hasNext()){


        flights.remove(itr.next());

    }

}

... 。

Exception in thread "main" java.util.ConcurrentModificationException
    at java.util.LinkedList$ListItr.checkForComodification(Unknown Source)
    at java.util.LinkedList$ListItr.next(Unknown Source)
    at section1.FlightQueue.clear(FlightQueue.java:44)
    at section1.FlightTest001.main(FlightTest001.java:22)

它有什么问题？不能理解为什么会给出错误，我确信我在arraylists或数组上使用了相同的代码并且它已经工作了。

Whats wrong with it? cant at all understand why the error is given, I am sure i have used the same code on arraylists or arrays and it has worked.

推荐答案

在迭代元素时，无法直接从集合中删除项目，因为这会导致 ConcurrentModificationException 。 Iterator.remove（）是在迭代期间修改集合的可接受的安全方法。为避免看到 IllegalStateException ，请务必调用 Iterator.next（）：

You cannot remove an item from the collection directly while iterating through the elements as this will cause a ConcurrentModificationException. Iterator.remove() is the accepted safe way to modify a collection during iteration. To avoid seeing an IllegalStateException, make sure to call Iterator.next():

while (itr.hasNext()) {
   itr.next();
   itr.remove();
}

或者你只想删除收藏，您可以使用：

or as you simply wish to remove all elements in the Collection, you could use:

flights.clear();

请参阅：在迭代集合时删除元素的高效等价物

See: Efficient equivalent for removing elements while iterating the Collection

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