LG Soft India Interview Questions and Answers

Access modifiers in Java control the visibility and accessibility of classes, methods, and variables.

• Access modifiers include public, private, protected, and default (no modifier).

• Public - accessible from any other class.

• Private - only accessible within the same class.

• Protected - accessible within the same package and subclasses.

• Default - accessible only within the same package.

• Access modifiers help in encapsulation, data hiding, and code reusability.

OOPs stands for Object-Oriented Programming. It is used in Java to organize code into objects for better reusability, maintainability, and scalability.

• OOPs allows for the creation of classes and objects, which encapsulate data and behavior together.

• It promotes concepts like inheritance, polymorphism, encapsulation, and abstraction.

• Using OOPs in Java leads to modular and organized code, making it easier to understand and maintain.

• For example, a car class can have attributes li...read more

Abstract class is a class that cannot be instantiated and may contain abstract methods.

• Cannot be instantiated directly

• May contain abstract methods that must be implemented by subclasses

• Can have both abstract and non-abstract methods

• Used to define a common interface for subclasses

React is a JavaScript library for building user interfaces. React components are reusable, self-contained building blocks of a UI.

• React is a JavaScript library for creating interactive UIs

• React components are reusable and self-contained

• Components can be nested within each other to create complex UI structures

• Components can have their own state and lifecycle methods

• React uses a virtual DOM to efficiently update the UI

An interface in Java is a reference type, similar to a class, that can contain only constants, method signatures, default methods, static methods, and nested types.

• Interfaces are used to define a contract for classes that implement them.

• Classes can implement multiple interfaces, but can only extend one class.

• Interfaces are used to achieve abstraction and multiple inheritance in Java.

• Example: interface Animal { void eat(); void sleep(); }

Hibernate is an open-source Java framework that simplifies database operations by mapping Java objects to database tables.

• Hibernate is an ORM (Object-Relational Mapping) tool.

• It provides a way to map Java classes to database tables and Java data types to SQL data types.

• Hibernate handles the mapping between Java objects and database tables, as well as the generation of SQL queries.

• It simplifies database operations by allowing developers to work with objects rather than SQL que...read more

Hooks in React are functions that allow you to use state and other React features in functional components.

• Hooks are introduced in React 16.8 as a way to write reusable logic in functional components.

• They allow you to use state and other React features without writing a class.

• Hooks provide a way to break down complex components into smaller, reusable functions.

• Some commonly used hooks are useState, useEffect, useContext, and useRef.

• Example: useState hook allows you to add sta...read more