Java Developer

• Explain your current project.
• Which technologies you have used in your current project?
• What is the reason for the switch?

You are given a string 'S' of length 'N', you need to find the frequency of each of the characters from ‘a’ to ‘z’ in the given string.

Example :

Given 'S' : abcdg
Then output will be : 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

What is an immutable class and how can we create an immutable class? (Learn)

What is the difference between an arraylist and a linked list? (Learn)

Using stream api find employee group by department.

What are wrapper classes and their advantages? (Learn)

What is the volatile keyword? (Learn)

What is a Garbage Collector and its types? (Learn)

Given a string 'S' of length 'L', return the length of the longest substring without repeating characters.

Example:

Suppose given input is "abacb", then the length of the longest substring without repeating characters will be 3 ("acb").

How does a HashMap work internally? What is the difference between a HashMap and a ConcurrentHashMap?