Java Collection Framework Quiz

Which of these is not a part of the Java Collection Framework?

• List

• Map

• Array

• Set

Which interface allows duplicate elements?

• Set

• Map

• List

• SortedSet

Which class is synchronized?

• ArrayList

• LinkedList

• HashMap

• Vector

Which of the following maintains insertion order?

• HashMap

• LinkedHashMap

• TreeMap

• Hashtable

Which class implements a doubly linked list?

• ArrayList

• LinkedList

• HashSet

• TreeSet

Which of the following does not allow null as a key?

• HashMap

• Hashtable

• LinkedHashMap

• TreeMap

Which interface does Queue extend?

• Set

• Map

• List

• Collection

Which collection class is best suited for LIFO operations?

• ArrayList

• LinkedList

• Stack

• TreeSet

Which method is used to sort a list in natural order?

• Collections.sort(list)

• list.sort()

• Arrays.sort(list)

• Collections.arrange(list)

What is the time complexity for inserting an element in a HashSet?

• O(n)

• O(log n)

• O(1) on average

• O(n log n)