Quiz — Heaps

A Java `PriorityQueue<Integer>` has 5, 1 and 3 added in that order, and a for-each loop prints every item. What does the loop print?

Hint

A for-each loop walks the array inside the queue. Is that array sorted, or only a heap?

The items in the order of the heap's array, which is not guaranteed to be sorted; calling poll repeatedly gives 1, 3, 5

1, 3, 5, because a priority queue keeps its items sorted

5, 1, 3, the order in which the items were added