There was a written test that contained 20 MCQs, two programs, and 2 SQL queries.

Then there were 3 technical interview rounds, one fitment round, and a final HR round.

I was referred by Headsn Mids Consultancy. The whole interview process took a complete day, from 10:30 AM to 9:00 PM.

Tell me about your current project.

Difference between method overloading and method overriding.

Can I override a private method?

Abstraction vs. interface.

Can we write the implementation of only a few methods if a class is implementing a particular interface?

Tell me about final for classes, methods, and variables.

As you said, if the value of a final method cannot be changed, then what will happen in the following case: final Person p = new Person("ABC", 24); p.setAge(25); If the above code runs properly with the updated age, why is it proper?

Tell me about exception handling.

In the discussion, an example for each answer was asked for: "Where in your project have you used this?" When should I throw a runtime custom exception, and when should I throw a checked exception? How do you create a custom exception? What is the need to create a custom exception? Example.

Do you know how exception handling works in case of inheritance? If a parent class has a method declared as follows: public String method1() throws IOException { ... } Then can I override this method as follows: public String method1() throws Exception { ... }?

No, then why? What about the vice versa?

Which collections have you used in your project?

What is an ArrayList? Do you know how an ArrayList works internally?

What is an array? Difference between an array and an ArrayList.

The discussion went around significance. When would I use which list or array: doubly linked list, linked list? Told about the internal implementation of a linked list, a doubly linked list, and so on.

Internal working of HashMap. Hashing and equals methods were focus points. Relationship between hashing and the equals method. If two objects have the same hash code, then is it necessary that they are actually equal? And vice-versa. Played around this question.

If I want to create a map of a custom object versus a String, e.g., Map<Person, String>, then what do I need to include in the Person class? How should I write the class?

Other than providing equals and hashCode functions, what else is required? Is it okay if the Person class is mutable? Write an immutable class.

Given a string sentence, get the duplicate words from it.