Anchanto Interview Questions and Answers

Static keyword is used to create class-level variables and methods that can be accessed without creating an instance of the class.

• Static variables are shared among all instances of a class

• Static methods can be called without creating an object of the class

• Static blocks are used to initialize static variables

• Static import is used to import static members of a class

Abstract class can have implementation while interface only has method signatures.

• Abstract class can have constructors while interface cannot.

• A class can implement multiple interfaces but can only extend one abstract class.

• Abstract classes can have non-abstract methods while interfaces cannot.

• Abstract classes can have instance variables while interfaces cannot.

• Interfaces can have default methods while abstract classes cannot.

Spring Boot is a framework for building standalone, production-grade Spring-based applications.

• Simplifies the process of creating and deploying Spring-based applications

• Provides a range of pre-configured features and dependencies

• Enables rapid development and prototyping

• Supports a variety of deployment options, including cloud-based platforms

• Offers a range of plugins and tools for development and testing

• Improves developer productivity and reduces time-to-market

List is an ordered collection while Set is an unordered collection of unique elements.

• List allows duplicate elements while Set does not.

• List maintains the insertion order while Set does not guarantee any order.

• List is implemented using ArrayList, LinkedList, etc. while Set is implemented using HashSet, TreeSet, etc.

• List has methods like get(), set(), add(), remove(), etc. while Set has methods like add(), remove(), contains(), etc.

Generics is a feature in Java that allows classes and methods to be parameterized by type.

• Generics provide type safety and reduce code duplication.

• They allow for the creation of reusable code.

• Example: List myList = new ArrayList();

• Example: public class MyClass { ... }

• Example: public void myMethod(T t) { ... }

Indexing in SQL is a technique to improve query performance by creating indexes on columns.

• Indexes are created on columns that are frequently used in WHERE, JOIN, and ORDER BY clauses.

• Indexes can be created using CREATE INDEX statement.

• Indexes can be unique or non-unique.

• Indexes can be clustered or non-clustered.

• Indexes can be dropped using DROP INDEX statement.