Nelito System Software Developer Interview Questions and Answers

React is a JavaScript library for building user interfaces.

• React is used for creating interactive UI components.

• It uses a virtual DOM for efficient rendering.

• React lifecycle methods include componentDidMount, componentDidUpdate, and componentWillUnmount.

• These methods allow developers to perform actions at specific points in a component's lifecycle.

Virtual DOM is a lightweight copy of the actual DOM used for efficient updates. Reconciliation is the process of updating the actual DOM based on changes in the virtual DOM.

• Virtual DOM is a lightweight copy of the actual DOM kept in memory.

• When changes are made to the UI, they are first reflected in the virtual DOM.

• Reconciliation is the process of comparing the virtual DOM with the actual DOM and updating only the nece...read more

To connect to the backend, you can use APIs, database connections, or web services.

• Use APIs to send and receive data between the frontend and backend

• Establish database connections to retrieve and store data

• Utilize web services for communication between different systems

A class is a blueprint for creating objects, while an object is an instance of a class. Private, protected, public, and default are access modifiers in object-oriented programming.

• A class is a template or blueprint that defines the properties and behaviors of objects.

• An object is an instance of a class, created using the class blueprint.

• Private access modifier restricts access to class members within the same class.

• Pro...read more

An object is a self-contained entity that consists of both data and behavior.

• Objects are instances of classes in object-oriented programming.

• They encapsulate data and provide methods to manipulate that data.

• Objects can interact with each other through method calls and message passing.

• Examples of objects include a car, a person, or a bank account.

Public is a keyword in programming languages that denotes the accessibility of a class, method, or variable.

• Public is one of the access modifiers in object-oriented programming.

• It allows the class, method, or variable to be accessed from any other class or package.

• Public members are part of the public API of a software component.

• Example: public class MyClass { ... }

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

• Example: public

In programming, private is an access modifier that restricts the visibility of a class member to within its own class.

• Private is used to encapsulate data and prevent direct access from outside the class.

• Private members can only be accessed through public methods or properties.

• Private variables are often used to store internal state or implementation details.

• Private methods are used for internal logic and are not meant

protected is an access modifier in object-oriented programming that restricts access to members within the same package or subclasses.

• protected is one of the four access modifiers in Java, along with public, private, and default.

• Members declared as protected can be accessed within the same package or by subclasses.

• Protected members are not accessible outside the package unless accessed through inheritance.

• Example: prot...read more