Reactjs Interview Questions in Tamil (Updated List 2024)

React.js is a javascript library used to build user inter phases. It’s made by Facebook, and lots of developers use it because it makes building websites easier. With React, you can make different parts of a website that do different things, and you can reuse those parts over and over again. It’s really good at making websites fast and smooth for people to use because it knows how to change only the stuff that needs to change, without redoing everything each time. React.js is one of the technical topics that you need to go through before attending a technical interview mainly for a full-stack web developer job. In this article, we will discuss React.js interview questions in Tamil ( Updated List 2024).

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React.js Interview Questions

What is React.js?

React.js is can be explained with the help of following points:

JavaScript Library:

• js is a JavaScript library.
• It’s used for building user interfaces (UIs) for web applications.

Component-Based:

• React follows a component-based architecture.
• UIs are built using reusable components.
• Components encapsulate both structure and behavior.

Declarative Syntax:

• React uses a declarative approach.
• Developers specify what they want to see in the UI.
• React takes care of updating the DOM to match the specified state.

Virtual DOM:

• React uses a virtual DOM.
• It optimizes rendering performance.
• Compares lightweight virtual DOM with the actual DOM to determine minimal changes needed.

Efficient Updates:

• React updates only the parts of the UI that have changed.
• It avoids re-rendering the entire page.
• Results in faster rendering speeds and improved user experience.

JSX:

• React uses JSX syntax.
• Allows writing HTML-like code within JavaScript.
• Makes it easier to create and maintain UI components.

 State Management:

• React provides a built-in mechanism for managing component state.
• Allows creating interactive and dynamic UIs.
• Responds to user input and application events.

Unidirectional Data Flow:

• React follows a unidirectional data flow.
• Data flows from parent to child components.
• Maintains data consistency and predictability.

Community Support:

• React has a large and active community of developers.
• Extensive documentation, tutorials, and resources available.
• Makes it easy to learn and adopt React.

Versatility:

• React can be used for various types of applications.
• Includes single-page applications (SPAs), progressive web apps (PWAs), mobile apps (using React Native), etc.
• Suitable for projects of any size and complexity.

Use of React.js

React.js is used for:

Single-Page Applications (SPAs):

• React helps build websites where everything happens on one page.
• You click something, and the page changes without loading a new one.

Dynamic Web Applications:

• React makes websites that react quickly to what you do.
• It can change parts of the page without reloading the whole thing.

Progressive Web Apps (PWAs):

• React can make websites that work like phone apps.
• They can work offline, send notifications, and load fast.

Mobile Applications:

• React can make apps for phones using the same code.
• Developers can write once and use it for both iOS and Android.

UI Components Libraries:

• React lets developers make reusable parts for websites.
• These parts can be used again and again, saving time and effort.

Enterprise Applications:

• React is good for big business apps because it can handle a lot of things at once.
• It keeps everything organized and works well even with lots of users.

E-commerce Websites:

• React helps make online stores fast and easy to use.
• You can search for items, see them quickly, and buy without waiting.

Social Media Platforms:

• React can make social media sites where things happen in real-time.
• You can post, like, and comment, and everything updates instantly.

Data Visualization Tools:

• React helps show data in charts and graphs that are easy to understand.
• You can see changes in data quickly and make decisions faster.

Content Management Systems (CMS):

• React makes it easy for people to manage and publish content online.
• Websites can have simple interfaces to add and change content without coding.

What are the features of React.js?

The feature of React.js:

Component-Based Architecture:

• React breaks down web pages into reusable parts called components.
• Makes it easier to build and maintain websites.

Virtual DOM:

• React uses a smart system to update web pages efficiently.
• Helps websites run faster and smoother.

JSX:

• React lets you write HTML-like code in JavaScript.
• Makes building web pages more straightforward.

Declarative Syntax:

• React lets you say what you want on the web page, and it figures out how to make it happen.
• Simplifies coding and reduces errors.

Unidirectional Data Flow:

• Data moves in one direction, from big parts of the page to smaller ones.
• Makes websites easier to understand and manage.

Efficient Updates:

• React only changes parts of the page that need updating, not the whole page.
• Keeps websites fast and responsive.

State Management:

• React helps manage the information needed to make web pages interactive.
• Makes it easier to build dynamic features like forms and animations.

Community Support:

• React has a large community of developers who share ideas and help each other.
• Lots of resources available to learn and get help.

Cross-Platform Development:

• React can be used to build websites, mobile apps, and even desktop apps.
• Saves time by allowing developers to use the same skills for different platforms.

Tooling and Developer Experience:

• React provides tools to make development easier, like debugging tools and project scaffolding.
• Helps developers work more efficiently and build better websites.

What are the Components of React.js?

The components of React.js are the building blocks of user inter-phase. They are:

Functional Components:

• Simple JavaScript functions.
• Return what should be shown on the screen.
• Used for basic UI parts.
• Do not remember information or handle complex tasks.

Class Components:

• JavaScript classes.
• Can remember information.
• Handle events and do complex tasks.
• Used for UI parts needing state management or event handling.

Hooks:

• Special functions for functional components.
• Allow functional components to use state and lifecycle features.
• Makes it easier for functional components to manage state or perform tasks at specific times.

React.js Interview Questions (Updated List 2024)

1. What is React.js?

• js is a JavaScript library developed by Facebook for building user interfaces (UIs) for web applications.

2. What are the key features of React.js?

• Key features include component-based architecture, virtual DOM, JSX syntax, unidirectional data flow, and efficient updates.

 3. What is JSX in React?

• JSX (JavaScript XML) is a syntax extension for JavaScript that allows writing HTML-like code within JavaScript, making it easier to create React components.

4. What are functional components in React?

• Functional components are JavaScript functions that return JSX elements, used for creating UI components in React.

5. Explain class components in React.

• Class components are JavaScript classes that extend the React. Component class, used for creating more complex UI components with state management and life-cycle methods.

6. What are props in React?

• Props (short for properties) are used to pass data from parent to child components in React, allowing components to be configured from outside.

7. How do you handle state in React?

• State in React is managed using the setState() method for class components and the useState() hook for functional components.

8. What are life-cycle methods in React?

• Life-cycle methods are special methods in class components that are invoked at different stages of a component’s life-cycle, such as mounting, updating, and unmounting.

9. Explain the concept of virtual DOM in React.

• The virtual DOM is a lightweight representation of the actual DOM in memory. React uses it to optimize rendering performance by comparing changes and selectively updating the DOM.

10. How does React handle events?

• React uses synthetic events, which are similar to native DOM events but have consistent behavior across different browsers. Event handlers are assigned using camelCase syntax.

11. What is conditional rendering in React?

• Conditional rendering is the practice of rendering different components or elements based on certain conditions or states in the application.

12. How do you update state in React?

• State in React can be updated using the setState() method for class components and the useState() hook for functional components.

13. Explain the concept of keys in React lists.

•  Keys are special attributes used in React lists to give each list item a unique identifier. They help React identify which items have changed, been added, or been removed.

14. What are controlled components in React?

• Controlled components are form elements whose value is controlled by React state. They allow React to have full control over the form’s data.

15. What is the difference between state and props in React?

• State is managed internally by a component and can be updated using setState(), while props are passed from parent to child components and cannot be modified by the child component.

 16. How do you create reusable components in React?

• Reusable components in React are created by defining functional or class components with specific functionalities and using them wherever needed in the application.

17. Explain the concept of higher-order components (HOC) in React.

• Higher-order components are functions that take a component as input and return a new component with enhanced functionality. They are used for code reuse and abstraction of common functionalities.

18. What are React hooks? Provide examples.

• React hooks are functions that allow functional components to use state and other React features. Examples include useState(), useEffect(), useContext(), etc.

19. Explain the difference between useEffect() and componentDidMount() in React.

• useEffect() is a hook used in functional components to perform side effects (like data fetching or DOM manipulation) after every render, while componentDidMount() is a lifecycle method in class components invoked after the component is mounted (inserted into the DOM tree).

20. Write a React component to display a list of items.

 jsx code

import React from ‘react’;

const ItemList = ({ items }) => {

return (

<ul>

{items.map(item => (

<li key={item.id}>{item.name}</li>

))}

</ul>

);

};

export default ItemList;

React.js Interview Questions in Tamil (Updated List 2024): Video

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React.js Interview Questions in Tamil (Updated List 2024): Conclusion

React.js is a javascript library used to build user inter phases. This is one of the common technologies used in the web development. Candidates attending technical interviews on full stack web development are expected to have the basic knowledge of Reat.js. In this article we have discusses some important interview questions based on this topic. We have also shared a detailed video of interview questions in Tamil language for those of you who understands Tamil.

React.js Interview Questions in Tamil (Updated List 2024): FAQs?

1. Why learning React.js for technical interview is important?

 Ans. Learning React.js for a technical interview is important because:

• It’s widely used in the industry, showing it’s important.
• Knowing it can help you get more jobs, especially in front-end development.
• Interviews often ask about React.js to see if you know it.
• Solving React problems shows you’re good at fixing things.
• It helps you be better at different kinds of web development.

2. What are the components of React.js?

Ans. The components of Reat.js are: functional components, class components and hooks.

3. What are the advantages of React.js?

Ans. The advantages of React.js include:

• Reusability: Components can be reused, making development faster.
• Virtual DOM: Efficiently updates the UI, improving performance.
• Component-based architecture: Encourages modular and scalable code.
• Strong community and ecosystem: Provides support and a wide range of libraries and tools.
• JSX syntax: Simplifies writing and maintaining UI code.