NeoSOFT Associate Software Engineer Interview Questions and Answers

This interview question covers various topics including abstract class, interface, HashMap, ArrayList, Linked List, String reversal, dependency injection, IOC container, and singleton class.

• Abstract class is a class that cannot be instantiated and can have both abstract and non-abstract methods.

• Interface is a blueprint of a class that can only have abstract methods and cannot be instantiated.

• HashMap is a data structure that stores key-value pairs and uses hashing to provide c...read more

Controller is a general term for handling requests, while Rest Controller is specifically for RESTful web services.

• Controller is responsible for handling incoming requests and returning responses.

• Rest Controller is a specialized type of controller that is used for building RESTful web services.

• Rest Controller uses HTTP methods like GET, POST, PUT, DELETE to perform CRUD operations on resources.

• Rest Controller returns data in JSON or XML format.

• Example: Spring MVC has a regula...read more

Stream API is a new feature in Java 8 that allows processing of collections in a functional way.

• Stream API provides a set of functional interfaces and methods to perform operations on collections.

• It supports parallel processing of collections, making it faster for large datasets.

• Examples of operations include filtering, mapping, sorting, and reducing.

• Stream API can be used with both primitive and object types.

• It promotes cleaner and more concise code compared to traditional l...read more

HashMap is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to determine the index in the array where it will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• To retrieve a value, the key is hashed again to find the corresponding index and then the linked list is sea...read more

Optional class in Java is used to represent a value that may or may not be present.

• Optional class was introduced in Java 8.

• It is used to avoid null pointer exceptions.

• It can be used with streams to filter out null values.

• Example: Optional name = Optional.ofNullable(null);

• Example: Optional name = Optional.of("John");