vanshikapandey30 / most-asked-interview-questions

Here are the most asked interview questions

Most-Asked-Interview-Questions

This repository aims to compile a collection of the most commonly asked interview questions. We invite you to contribute by sharing your interview experiences and questions encountered. Feel free to submit a pull request (PR) with your contributions in the appropriate section.

JavaScript Developer Interview Questions:

1. What is JavaScript, and what are its key features?
2. Explain the difference between == and === in JavaScript.
3. What is the difference between let, const, and var in JavaScript? When would you use each?
4. What is closure in JavaScript? Provide an example.
5. How does prototypal inheritance work in JavaScript?
6. What are the different data types in JavaScript?
7. Describe event bubbling and event capturing in JavaScript.
8. Explain the difference between null and undefined in JavaScript.
9. What are the different ways to declare variables in JavaScript?
10. How does Asynchronous JavaScript work, and what are the different techniques to handle it?
11. What is the purpose of the this keyword in JavaScript? How is its value determined?
12. Explain the concept of hoisting in JavaScript.
13. What are arrow functions in JavaScript? How do they differ from regular functions?
14. What is the purpose of the Promise object in JavaScript? How do you use it?
15. How does the async/await syntax work in JavaScript? How does it improve asynchronous code readability?
16. What are the key differences between map, filter, and reduce in JavaScript? Provide examples of each.
17. Explain the concept of scope in JavaScript. How does lexical scoping work?
18. What is a callback function in JavaScript? Provide an example of how you would use one.
19. What are the different ways to handle errors in JavaScript?
20. Describe the concept of a higher-order function in JavaScript. Provide an example.
21. What is the difference between synchronous and asynchronous code execution in JavaScript?
22. Describe the difference between the for...in loop and the for...of loop in JavaScript.
23. Explain the difference between map and forEach in JavaScript.
24. What are the differences between splice and slice in JavaScript? Provide examples of each.

React Developer Interview Questions:

1. What is React, and what are its key features?
2. Why do some developers prefer React over Angular and Vue.js?
3. Give the two most significant drawbacks of React.
4. Explain the difference between class components and functional components in React.
5. What is JSX, and why is it used in React?
6. What are React Fragments, and why are they used?
7. What are the lifecycle methods in React, and how do they work?
8. What is state in React, and how is it managed?
9. Describe the concept of virtual DOM in React.
10. What is Babel in React js ?
11. What are React Hooks, and how do they differ from class-based components?
12. How does React Router work, and what are its key components?
13. Describe the concept of context in React. How is it used to pass data through the component tree?
14. What are controlled components in React? Provide an example.
15. What are the main difference between Pros and State ?
16. What are React Hooks, and how do they differ from class-based components?
17. Explain the concept of Higher Order Components (HOCs) in React.
18. Describe the concept of context in React. How is it used to pass data through the component tree?
19. What is the Flux architecture, and how does it differ from traditional MVC?
20. What is Redux, and how does it complement React?
21. How does Redux handle state management in a React application?
22. What is the 'Store' feature in Redux, and how does it manage application state?
23. Explain the role of the dispatcher in Redux and how it facilitates the flow of actions to reducers.
24. How do you optimize performance in a React application?

Java Developer Interview Questions:

1. What are the main features of Java programming language?
2. Explain the difference between == and .equals() in Java.
3. What are the access modifiers in Java, and what do they mean?
4. What is the difference between ArrayList and LinkedList in Java?
5. What is method overloading and method overriding in Java?
6. How does exception handling work in Java? Provide an example.
7. What is the difference between final, finally, and finalize in Java?
8. Explain the concept of multithreading in Java.
9. What are the different types of inheritance in Java?
10. What is the purpose of the static keyword in Java?

Web Developer Interview Questions:

1. What is the difference between HTTP and HTTPS?
2. Explain the concept of CORS (Cross-Origin Resource Sharing) in web development.
3. How do you ensure your website is accessible to users with disabilities?
4. What is the box model in CSS, and how does it work?
5. Describe the difference between inline, block, and inline-block elements in CSS.
6. What are media queries in CSS, and how are they used for responsive web design?
7. What is the purpose of the viewport meta tag in HTML?
8. How do you optimize website performance and loading speed?
9. Explain the difference between cookies, local storage, and session storage in web development.
10. What are the advantages and disadvantages of using CSS preprocessors like Sass or Less?
11. Describe the differences between client-side scripting and server-side scripting in web development.
12. Explain the purpose of a content delivery network (CDN) and how it improves website performance.
13. What are the benefits of using responsive web design principles in modern web development?
14. Describe the process of optimizing a website for search engines (SEO).
15. How do you ensure your website is secure from common vulnerabilities such as cross-site scripting (XSS) and SQL injection?
16. What are some best practices for designing and developing a mobile-first website?
17. How do you approach optimizing images and multimedia content for the web?
18. Describe the importance of web standards and how they impact web development.
19. How would you implement lazy loading of images on a website to improve performance?
20. Can you explain the concept of progressive web apps (PWAs) and their benefits over traditional web apps?

Backend Developer Interview Questions:

1. What is the difference between frontend and backend development?
2. Explain the MVC (Model-View-Controller) architecture pattern.
3. Describe the role of databases in backend development, and list some popular database systems.
4. What is RESTful API, and how does it work?
5. Explain the difference between stateful and stateless communication in backend systems.
6. What is authentication and authorization in backend development? How are they implemented?
7. Describe the concept of middleware in backend frameworks like Express.js.
8. How does caching work in backend systems, and what are its benefits?
9. What are microservices, and how do they differ from monolithic architectures?
10. Discuss the importance of security in backend development, and list some common security vulnerabilities and how to mitigate them.

MongoDB Interview Questions:

1. What is MongoDB?
2. What are the key features of MongoDB?
3. Explain the concept of BSON in MongoDB.
4. What is Sharding in MongoDB?
5. What is the difference between MongoDB and MySQL?
6. Explain the concept of indexing in MongoDB.
7. What is a Replica Set in MongoDB?
8. Explain the concept of GridFS in MongoDB.
9. What is the role of Mongoose in MongoDB?
10. What is the significance of the ObjectId in MongoDB?
11. How does MongoDB ensure high availability?
12. What is the role of the WiredTiger storage engine in MongoDB?
13. Explain the concept of Aggregation in MongoDB.
14. What are the different types of NoSQL databases, and how does MongoDB differ from them?
15. How does MongoDB provide flexibility in schema design?
16. What is the significance of write concern in MongoDB?
17. Explain the concept of capped collections in MongoDB.
18. What is TTL (Time To Live) in MongoDB?
19. How does MongoDB handle transactions?
20. What are the best use cases for MongoDB?

SQL Interview Questions

1. What is SQL?
2. Differentiate between SQL and MySQL.
3. Explain the difference between DELETE and TRUNCATE commands.
4. What is a primary key and foreign key in SQL?
5. Explain the difference between CHAR and VARCHAR data types.
6. What is the purpose of the GROUP BY clause?
7. What is the difference between INNER JOIN and OUTER JOIN?
8. What is a subquery in SQL?
9. How do you handle NULL values in SQL?
10. What is the purpose of the HAVING clause?
11. Explain the difference between UNION and UNION ALL.
12. How do you optimize SQL queries?
13. What is normalization and denormalization in SQL?
14. Explain the difference between clustered and non-clustered indexes.
15. How do you find duplicate records in a table?
16. What is an alias in SQL? Provide an example.
17. How do you update data in a table using SQL?
18. What is the purpose of the CASE statement in SQL?
19. Explain the difference between a view and a table.
20. How do you perform a backup and restore in SQL Server?