NodeJS Interview Cheat Sheet

1. What is Node.js?

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2. Why was Node.js created?

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3. What is the V8 engine in Node.js?

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4. What is the event loop in Node.js?

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5. What is single-threaded architecture?

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6. What is npm?

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7. What is a package.json file?

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8. What are dependencies and devDependencies?

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9. What is a callback function?

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10. What is a module in Node.js?

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11. What is CommonJS?

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12. What is the fs module used for?

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13. What is the path module used for?

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14. What is the os module?

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15. What is a buffer in Node.js?

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16. What is a stream in Node.js?

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17. What is server-side JavaScript?

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18. What is the http module used for?

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19. What is middleware?

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20. What is Express.js?

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21. What is routing in Node and Express?

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22. What is JSON in Node.js?

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23. What is an API endpoint?

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24. What is an environment variable?

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25. What is process.env?

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26. What is nodemon?

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27. What is asynchronous programming in Node?

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28. What is synchronous programming?

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29. What is an error-first callback?

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30. Difference between console.log and return?

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31. What is the difference between synchronous and asynchronous file operations in Node.js?

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32. What is the role of the event emitter?

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33. How does Node.js handle concurrency if it is single-threaded?

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34. What is middleware chaining in Express.js?

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35. What is CORS and why is it needed?

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36. What is the difference between PUT and PATCH?

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37. What is the purpose of Express.js router?

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38. How does Node.js handle errors in asynchronous code?

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39. What is a promise in Node.js?

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40. What is async/await and why is it useful?

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41. What is the purpose of the cluster module in Node.js?

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42. What is rate limiting in Node.js?

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43. What are HTTP status codes and why are they important?

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44. What is streaming in Node.js?

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45. What is a template engine in Node.js?

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46. What is JSON Web Token (JWT)?

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47. What is the difference between global and local npm installation?

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48. What is nodemailer and where is it used?

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49. What is dotenv and why is it used?

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50. What is body parsing in Express.js?

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