1.
What are Collection related features in Java 8?
2.
What is Java Collections Framework? List out
some benefits of Collections framework?
3.
What is the benefit of Generics in Collections
Framework?
4.
What are the basic interfaces of Java
Collections Framework?
5.
Why Collection doesn’t extend Cloneable and
Serializable interfaces?
6.
Why Map interface doesn’t extend Collection
interface?
7.
What is an Iterator?
8.
What is difference between Enumeration and
Iterator interface?
9.
Why there is not method like Iterator.add() to
add elements to the collection?
10.
Why Iterator don’t have a method to get next
element directly without moving the cursor?
11.
What is different between Iterator and ListIterator?
12.
What are different ways to iterate over a list?
13.
What do you understand by iterator fail-fast
property?
14.
What is difference between fail-fast and
fail-safe?
15.
How to avoid ConcurrentModificationException
while iterating a collection?
16.
Why there are no concrete implementations of
Iterator interface?
17.
What is UnsupportedOperationException?
18.
How HashMap works in Java?
19.
What is the importance of hashCode() and
equals() methods?
20.
Can we use any class as Map key?
21.
What are different Collection views provided by
Map interface?
22.
What is difference between HashMap and
Hashtable?
23.
How to decide between HashMap and TreeMap?
24.
What are similarities and difference between
ArrayList and Vector?
25.
What is difference between Array and ArrayList?
When will you use Array over ArrayList?
26.
What is difference between ArrayList and
LinkedList?
27.
Which collection classes provide random access
of it’s elements?
28.
What is EnumSet?
29.
Which collection classes are thread-safe?
30.
What are concurrent Collection Classes?
31.
What is BlockingQueue?
32.
What is Queue and Stack, list their differences?
33.
What is Collections Class?
34.
What is Comparable and Comparator interface?
35.
What is difference between Comparable and Comparator
interface?
36.
How can we sort a list of Objects?
37.
While passing a Collection as argument to a
function, how can we make sure the function will not be able to modify it?
38.
How can we create a synchronized collection from
given collection?
39.
What are common algorithms implemented in
Collections Framework?
40.
What is Big-O notation? Give some examples?
41.
What are best practices related to Java
Collections Framework?
42.
What is Java Priority Queue?
43.
Why can’t we write code as List numbers
= new ArrayList();?
44.
Why can’t we create generic array? or write code
as List[] array = new ArrayList[10];
