Convert a Queue to List

Question

What is the fastest way to convert a Queue into a List while keeping the Queue order?

Answer 1

If you're converting from PriorityQueue to a List, remember that it is in fact a heap, so the ordering is determined using the poll() method, in which case, doing it by the constructor way as discussed in some of the other answers here, won't preserve the natural ordering of the queue.

Taking that into consideration, you can go along these lines:

List result = new ArrayList<>(yourPriorityQueue.size());
while (!yourPriorityQueue.isEmpty()) {
    result.add(yourPriorityQueue.poll());
}