PriorityQueue and Concurrent Modification

[Simran Dass]

Should not the following code give ConcurrentModificationException as we are
using the for-each loop and doing poll() on the PriorityQueue

	PriorityQueue<Integer>   pq2 = new  PriorityQueue<Integer>();
	pq2.offer(2);
	pq2.offer(4);

	for( Integer i : pq2){
		System.out.println("============="+pq2.poll() );
	}

The output is =============== 2.

Could not understand why this is happening ??

[Paul Clapham]

I don't see anything in the API documentation for the iterator() method of PriorityQueue which suggests it might do that.

[Henry Wong]

Agreed. Modifying a collection while iterating is not a good idea because you can get a concurrent modification exception. It doesn't mean that you always will.

Henry