Java Programming - MCQ Practice Questions

Which collection implementation is best for frequent insertions and deletions at both ends?

What is the purpose of the fail-fast iterator in Collections?

Consider a TreeMap with Integer keys. What will headMap(10) return?

Which collection interface guarantees that elements are stored in a sorted order with no duplicates?

Which collection would you use if you need to maintain a sorted order of elements and also need O(log n) insertion/deletion time complexity?

Which of the following statements is true about PriorityQueue?

What is the time complexity of get() operation on a LinkedHashMap with n elements?

Which collection interface should be used if you need both key-value pairing and need to iterate in the order of keys' natural ordering?

What will be printed? Queue<Integer> queue = new LinkedList<>(); queue.add(10); queue.add(20); queue.add(30); System.out.println(queue.poll()); System.out.println(queue.peek());