Day 7 - Collection, Multithreading

Which interface provides the foundation for the collection hierarchy?

• Collection
• List
• Set
• Map

Which class implements the List interface and allows duplicates?

• HashSet
• TreeSet
• ArrayList
• LinkedHashSet

Which collection class allows you to store elements in a key-value pair?

• Set
• List
• Map
• Queue

Which class maintains insertion order in Java?

• HashMap
• TreeMap
• LinkedHashMap
• HashSet

Which of the following is not part of the Java Collection Framework?

• HashMap
• Vector
• Enumeration
• Array

Which class is synchronized in Java collections?

• ArrayList
• LinkedList
• HashMap
• Vector

Which collection class stores elements in sorted order?

• ArrayList
• TreeSet
• HashSet
• LinkedList

Which method is used to remove all elements from a collection?

• delete()
• clear()
• removeAll()
• purge()

Which of these does not allow null key?

• HashMap
• TreeMap
• LinkedHashMap
• Hashtable

Which interface does TreeSet implement?

• List
• SortedSet
• Queue
• Map