Can we insert null in hashset?
How do you sort a collection in descending order?
Differentiate between arraylist and vector.
How does a binary search work?
Is set sorted?
Explain merge sort algorithms.
What do u mean by array?
What is the difference between 1d and 2d array?
Does treemap allow null key?
How many types of priority queue are there?
What is sorting explain?
What is peek in stack?
Can arraylist have duplicates?