What is a hashmap used for?
What happens if constructor is private?
What is initial size of arraylist in java?
What a static class can contains?
Why we used vector class?
How to Sort list of Strings in ascending order without using java api.
Is 9 a prime number?
What is visibility mode?
Why do we need singleton?
What are the concepts of 'OOPS'?
What is hashmap in java?
How do you change an int to a string?
Write a regular expression to validate a password. A password must start with an alphabet and followed by alphanumeric characters; its length must be in between 8 to 20.