Why null is allowed in hashmap?
How efficient is binary search?
Explain about set and their types in a collection?
Do you know what is linear search?
How do we find duplicate elements in an array?
Define a binary search tree?
How do I sort hashset?
What are the different types of linked list?
What is a hash index?
What is a 2 dimensional array?
What are priority queues?
What is the difference between hashmap and arraylist?
What is the Role of push() and pop() method?