Top JavaScript Interview Questions and Answers in Tamil (2024)

JS or JavaScript is a programming language of world wide web along with HTML and CSS. It’s a high level language used for creating interactive content in the web. It used for both front end and back end development in full stack web development. It is also one of the technical topics that the interviewers try to cover during the interview process. In this article we will discuss JavaScript Interview Questions in Tamil for 2024.

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What is JavaScript?

JavaScript is a programming language used to make dynamic websites. It is used to add special features to the website like animation, form validation, user interaction etc. It can also be used for server side scripting to run on servers using Node.js. It also allows client side scripting in web browsers.

What JavaScript is used for?

JavaScript is used for:

Enhancing Website Interactivity:

• Adds interactive elements, updates content dynamically.
• Enhances user engagement, improves user experience.

Client-Side Validation:

• Validates user input, provides immediate feedback.
• Prevents submission errors, ensures data accuracy.

Dynamic Content Updates:

• Updates content without page reload, real-time data display.
• Enhances responsiveness, reduces page load time.

Creating Web Games:

• Develops browser-based games, from simple to complex.
• Provides immersive gaming experiences, entertains users.

Building Web Applications:

• Creates modern web apps with rich interfaces.
• Facilitates seamless navigation, boosts productivity.

Handling Browser Events:

• Responds to clicks, movements, keyboard inputs.
• Enables interactive features, enhances user interaction.

AJAX (Asynchronous JavaScript and XML):

• Retrieves and updates data without page reload.
• Improves performance, delivers dynamic content.

Animating Web Elements:

• Adds animations and transitions to web elements.
• Captivates audience attention, enhances visual appeal.

Creating Browser Games:

• Develops interactive games playable in web browsers.
• Expands gaming accessibility, reaches wider audience.

Implementing Browser Extensions:

• Enhances browser functionality, customizes browsing experience.
• Extends browser capabilities, improves workflow efficiency.

Benefits of Using JavaScript:

Versatility:

• Can be used for both making websites look good (front-end) and doing the behind-the-scenes work (back-end).
• Works on computers, phones, and other devices.

Ease of Use:

• Easy to learn and write because it has simple rules.
• Good for beginners and experts alike.

Interactivity:

• Makes websites more fun by letting you do things like click buttons and see changes without refreshing the page.
• Keeps users engaged and interested.

Rich Ecosystem:

• Lots of extra tools and ready-made parts available to help build things quickly.
• Many people use it, so there’s lots of help and advice online.

Asynchronous Capabilities:

• Can do tasks in the background without slowing down the main work.
• Makes web pages faster and more responsive.

Browser Compatibility:

• Works the same way on different web browsers like Chrome, Firefox, and Safari.
• Ensures that websites look and work well for everyone.

Fast Execution:

• Runs quickly in web browsers, so websites load faster.
• Makes sure users don’t have to wait too long for things to happen.

Platform Independence:

• Can run on lots of different devices, like computers, phones, and tablets.
• Makes it easy to build apps that work everywhere.

Real-Time Updates:

• Lets websites show new information instantly without refreshing the page.
• Useful for things like live chat and updating scores in games.

 Scalability:

• Can handle small projects and big ones equally well.
• Good for making websites grow as more people use them.

Limitations of Using JavaScript:

 Browser Differences:

•  Works differently in different web browsers.
• Needs to be adapted for each browser to work well.

 Security Concerns: 

• Can be vulnerable to hacking attacks.
• Needs careful handling to keep data safe.

Not the Fastest:

• Runs slower than some other programming languages.
• Can slow down websites if not optimized.

 Limited Multitasking: 

• Can only do one thing at a time.
• Might not be great for apps that need to do many things at once.

Needs Internet Connection: 

• Relies on being connected to the internet.
• Can’t do much if offline without extra tools.

 Hard to Find Mistakes: 

• Finding and fixing problems can be tricky.
• Needs lots of testing to make sure it works well.

 Visible Code: 

• Code is easy to see and change for anyone who visits a website.
• Can be risky if not handled carefully.

 Can Get Messy: 

• Code can become hard to understand in big projects.
• Needs to be organized well to avoid confusion.

 Memory Management: 

• Can sometimes use up too much memory.
• Needs to be watched carefully to avoid slowing things down.

 Access Restrictions: 

• Limited in how it can access data on different websites.
• Needs special permission to get data from other places.

 Companies that uses JavaScript in their Tech Stacks:

Google:

• Google uses JavaScript for building its web applications like Gmail, Google Maps, and Google Docs.
• They also created AngularJS, a tool for making interactive websites, which is also widely used.

Facebook:

• Facebook relies on JavaScript to make its website work smoothly.
• They made React, a special tool to help make Facebook and other websites look good and work fast.

Amazon:

• Amazon uses JavaScript to build the part of their website where you buy things.
• They also use Node.js to help make the behind-the-scenes parts of the website run well.

Netflix:

• Netflix uses JavaScript to make its website and apps look and feel nice when you’re watching movies.
• They also use Node.js to help manage all the information that’s needed to recommend movies to you.

Microsoft:

• Microsoft uses JavaScript to make its websites and online tools work well.
• They created TypeScript, a special kind of JavaScript that helps make websites safer and easier to build.

Uber:

• Uber uses JavaScript to make its app work smoothly when you book a ride.
• They use special tools like React and AngularJS to make the app look nice and easy to use.

Airbnb:

• Airbnb uses JavaScript to make its website and app work well when you book a place to stay.
• They use React to make different parts of the website look nice and work fast.

Twitter:

• Twitter uses JavaScript to make its website work smoothly when you tweet or read tweets.
• They also use Node.js to help manage all the information from millions of tweets.

LinkedIn:

• LinkedIn uses JavaScript to make its professional networking website easy to use.
• They use tools like Ember.js and React to make the website look nice and work smoothly.

Slack:

• Slack uses JavaScript to make its messaging app work smoothly on your computer.
• They use React and Electron to make the app look nice and work well on different devices.

JavaScript Interview Questions for 2024

1. What is JavaScript?

• JavaScript is a high-level, interpreted programming language used to make web pages interactive.

2. What are the different data types in JavaScript?

• Primitive data types include string, number, boolean, null, undefined, symbol. Objects are another data type.

3. What is the difference between null and undefined?

• null represents the intentional absence of any value.
• undefined means a variable has been declared but has not yet been assigned a value.

4. What is closure in JavaScript?

• A closure is an inner function that has access to the variables in the outer (enclosing) function’s scope chain.

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5. What is the purpose of the this keyword in JavaScript?

• The this keyword refers to the object it belongs to, which can vary depending on how a function is called.

6. What are the different ways to declare variables in JavaScript?

• Using var, let, or const. var has function scope, while let and const have block scope.

7. What is event bubbling in JavaScript?

• Event bubbling is the process where an event propagates through its ancestors in the DOM tree until it reaches the root.

8. What is the difference between == and === operators in JavaScript?

• == checks for equality after type conversion.
• === checks for equality without type conversion (strict equality).

9. What are arrow functions in JavaScript?

• Arrow functions are a shorter syntax for writing function expressions, introduced in ES6.

10. What is the use strict directive in JavaScript?

• “use strict”; is a directive that enables strict mode, which helps catch common coding mistakes and makes JavaScript more secure.

11. How do you check the type of a variable in JavaScript?

• Using the typeof operator. For example, typeof 42 returns “number”.

12. What is hoisting in JavaScript?

• Hoisting is JavaScript’s default behavior of moving variable and function declarations to the top of their containing scope during compilation.

 13. What is the purpose of setTimeout() function in JavaScript?

• setTimeout() is used to execute a function after a specified amount of time has elapsed.

14. What is the fetch API in JavaScript used for?

• The fetch API is used to make network requests (e.g., fetching data from a server) using promises.

15. What is the purpose of the map() function in JavaScript?

• The map() function is used to create a new array by applying a function to each element of an existing array.

16. What is the difference between splice() and slice() methods in JavaScript?

• splice() modifies the original array by removing or replacing elements.
• slice() returns a new array containing a portion of the original array.

17. What are JavaScript promises?

• Promises represent the eventual completion or failure of an asynchronous operation and allow handling asynchronous operations more easily.

18. What is the purpose of JSON.stringify() in JavaScript?

• stringify() is used to convert JavaScript objects into JSON strings.

19. Write a function to reverse a string in JavaScript.

javascript code

function reverseString(str) {

return str.split(”).reverse().join(”);

}

20. Write a function to check if a given number is prime in JavaScript.

javascript code

function isPrime(num) {

if (num <= 1) return false;

for (let i = 2; i <= Math.sqrt(num); i++) {

if (num % i === 0) return false;

}

return true;

}

21. Write a function to find the maximum number in an array.

javascript code

function findMax(arr) {

return Math.max(…arr);

}

22. Write a function to count the number of vowels in a string.

javascript code

function countVowels(str) {

const vowels = ‘aeiouAEIOU’;

let count = 0;

for (let char of str) {

if (vowels.includes(char)) {

count++;

}

}

return count;

}

23. Write a function to check if a string is a palindrome.

 javascript code

function isPalindrome(str) {

return str === str.split(”).reverse().join(”);

}

24. Write a function to remove duplicates from an array.

javascript code

function removeDuplicates(arr) {

return Array.from(new Set(arr));

}

25. Write a function to check if two strings are anagrams of each other.

javascript code

function areAnagrams(str1, str2) {

const sortedStr1 = str1.split(”).sort().join(”);

const sortedStr2 = str2.split(”).sort().join(”);

return sortedStr1 === sortedStr2;

}

JavaScript Interview Questions in Tamil for 2024: Video

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JavaScript Interview Questions in Tamil for 2024: Conclusion

JavaScript is a high level programming language used in web development. Large number of companies use JavaScript in their technology stack. In this article we have discussed some important JavaScript interview questions for 2024. A video in Tamil is also shared for the candidates who understand Tamil explaining all the interview questions in Tamil.

JavaScript Interview Questions in Tamil for 2024: FAQs?

1. How to prepare for technical interview on JavaScript?

Ans. Go through the previous technical questions by talking to candidates who have already attended the interview. Few questions are discussed above in this blog.

 2. What is JavaScript?

Ans. JavaScript is a programming language used to make dynamic websites. It is used to add special features to the website like animation, form validation, user interaction etc. It can also be used for server side scripting to run on servers using Node.js. It also allows client side scripting in web browsers.

3. Mentions some companies which uses JavaScript.

Ans. JavaScript is used by several companies like: Facebook, google, twitter,LinkedIn etc.