NTT Data Associate/Senior Associate -(Technical) Interview Questions, Process, and Tips

Real-time examples of OOP concepts

• Inheritance: A car is a vehicle, inheriting properties of a vehicle

• Polymorphism: A shape can be a square or a circle, both implementing the same area method

• Abstraction: A TV remote has buttons to perform actions, but the user doesn't need to know how it works internally

• Encapsulation: A bank account has private data like balance, which can only be accessed through public methods

SQL query to print rows with no match in a second table

• Use LEFT JOIN to join the two tables

• Filter the rows where the second table's primary key is NULL

• SELECT the columns from the first table

HashMap is a data structure that stores key-value pairs and allows fast retrieval of values based on keys.

• HashMap is part of the Java Collections Framework.

• It uses hashing to store and retrieve elements.

• It allows null values and null keys.

• It is not synchronized by default, but can be made synchronized using Collections.synchronizedMap() method.

• Example: HashMap map = new HashMap<>(); map.put("apple", 1)

Final, finally and finalise are related to completion or conclusion, but have different meanings and usage.

• Final is an adjective used to describe the last or ultimate stage of something.

• Finally is an adverb used to indicate the end of a process or event after a long wait or delay.

• Finalise is a verb used to complete or finish something, often with a formal or official process.

• Examples: The final exam, finally finished t

Different types of DBMS, DB languages & difference between drop, delete & truncate.

• Types of DBMS: Relational, NoSQL, Object-oriented, Hierarchical, Network, etc.

• Database languages: SQL, PL/SQL, T-SQL, etc.

• DROP: Deletes a table and its data, cannot be rolled back.

• DELETE: Deletes rows from a table, can be rolled back.

• TRUNCATE: Deletes all rows from a table, cannot be rolled back.