DevAcademy

1. What engine is Node.js built on?

SpiderMonkeyV8ChakraJavaScriptCore

2. What is a key difference between Node.js and browser JavaScript?

Node.js uses a different programming languageNode.js provides server-side APIs like file system access instead of DOM APIsNode.js cannot use variablesThere is no difference at all

3. Which of these is a common Node.js use case?

Styling web pages with CSSBuilding a web server or APIRendering 3D graphics in a browserWriting HTML markup

4. What does nvm let you do?

Manage npm packagesSwitch between installed Node.js versionsDeploy applicationsWrite TypeScript

5. Which release line is recommended for production applications?

CurrentLTS (Long-Term Support)NightlyBeta

6. Does installing Node.js also install npm?

No, npm must be installed separatelyYes, npm ships alongside Node.jsOnly on WindowsOnly with nvm

7. How many main threads does a Node.js process run JavaScript on?

OneOne per CPU coreUnlimitedIt depends on the framework

8. What is libuv responsible for?

Compiling JavaScriptProviding the event loop and a thread pool for I/OStyling the terminal outputManaging npm packages

9. Why can a CPU-heavy synchronous task be a problem in Node.js?

It cannot run at allIt blocks the single main thread, delaying every other request until it finishesIt automatically crashes the serverIt only affects the thread pool, not the main thread

10. What does npm install -D typescript do differently from npm install typescript?

Nothing, they are identicalIt adds typescript as a devDependency instead of a regular dependencyIt installs an older versionIt installs typescript globally

11. What is the purpose of package-lock.json?

It lists only devDependenciesIt records the exact resolved versions of every dependency for consistent installsIt stores environment variablesIt is optional and safe to delete anytime

12. What does npm install (with no package name) do?

Installs npm itselfInstalls every dependency listed in package.jsonUpdates Node.jsRemoves node_modules

13. What does the scripts field in package.json define?

Dependency versionsNamed commands runnable with npm runThe project's licenseEnvironment variables

14. What does the caret (^) mean in a version like "^4.19.2"?

Exactly this version, nothing elseThis version or any later compatible version within the same major versionAny version at allOnly patch-level updates

15. What shorthand exists for npm run start?

npm startnpm runnpm goThere is no shorthand

16. What is the CommonJS equivalent of ES Modules' export?

export.defaultmodule.exportsexports.moduledefine()

17. What does "type": "module" in package.json do?

Nothing, it is ignoredMakes .js files use ES Modules syntax by default instead of CommonJSDisables npmForces TypeScript

18. Is a file extension required when importing a local file with ES Modules?

No, neverYes, it is required (e.g. ./math.js)Only for CommonJSOnly in production

19. Why can't browser JavaScript directly read arbitrary files from disk, but Node.js can?

Browsers do not support JavaScript file operations at allBrowser JavaScript is sandboxed for security; Node.js runs with direct system accessThere is no real differenceOnly Chrome supports file access

20. Why should readFileSync() be avoided in a running web server?

It does not exist in Node.jsIt blocks the event loop, freezing every other in-flight request until it finishesIt only works with .txt filesIt is deprecated

21. What does fs/promises provide?

A synchronous-only APIA promise-based API usable with async/awaitOnly directory operationsA replacement for npm

22. Why does the path module exist instead of manually building paths with string concatenation?

It is faster onlyDifferent operating systems use different path separators, and path handles this correctlyIt has no real purposeIt only matters for URLs

23. What does path.extname("photo.jpg") return?

"photo"".jpg""jpg""photo.jpg"

24. Are dirname and filename automatically available in ES Modules the same way as CommonJS?

Yes, identicallyNo, they must be derived manually using import.meta.urlOnly on LinuxOnly in TypeScript

25. What does os.platform() return?

The Node.js versionThe operating system, like "darwin" or "linux"The current directoryThe npm version

26. What is a common use for os.cpus().length?

Reading a fileDeciding how many worker processes to spawnParsing a URLHashing a password

27. What does os.tmpdir() return?

The project root directoryA safe, OS-appropriate location for temporary filesThe current user's emailThe npm cache directory

Node.js Beginner Practice

Quick Quiz

1. What engine is Node.js built on?

2. What is a key difference between Node.js and browser JavaScript?

3. Which of these is a common Node.js use case?

4. What does nvm let you do?

5. Which release line is recommended for production applications?

6. Does installing Node.js also install npm?

7. How many main threads does a Node.js process run JavaScript on?

8. What is libuv responsible for?

9. Why can a CPU-heavy synchronous task be a problem in Node.js?

10. What does npm install -D typescript do differently from npm install typescript?

11. What is the purpose of package-lock.json?

12. What does npm install (with no package name) do?

13. What does the scripts field in package.json define?

14. What does the caret (^) mean in a version like "^4.19.2"?

15. What shorthand exists for npm run start?

16. What is the CommonJS equivalent of ES Modules' export?

17. What does "type": "module" in package.json do?

18. Is a file extension required when importing a local file with ES Modules?

19. Why can't browser JavaScript directly read arbitrary files from disk, but Node.js can?

20. Why should readFileSync() be avoided in a running web server?

21. What does fs/promises provide?

22. Why does the path module exist instead of manually building paths with string concatenation?

23. What does path.extname("photo.jpg") return?

24. Are dirname and filename automatically available in ES Modules the same way as CommonJS?

25. What does os.platform() return?

26. What is a common use for os.cpus().length?

27. What does os.tmpdir() return?

Node.js Beginner Practice

Quick Quiz

1. What engine is Node.js built on?

2. What is a key difference between Node.js and browser JavaScript?

3. Which of these is a common Node.js use case?

4. What does nvm let you do?

5. Which release line is recommended for production applications?

6. Does installing Node.js also install npm?

7. How many main threads does a Node.js process run JavaScript on?

8. What is libuv responsible for?

9. Why can a CPU-heavy synchronous task be a problem in Node.js?

10. What does npm install -D typescript do differently from npm install typescript?

11. What is the purpose of package-lock.json?

12. What does npm install (with no package name) do?

13. What does the scripts field in package.json define?

14. What does the caret (^) mean in a version like "^4.19.2"?

15. What shorthand exists for npm run start?

16. What is the CommonJS equivalent of ES Modules' export?

17. What does "type": "module" in package.json do?

18. Is a file extension required when importing a local file with ES Modules?

19. Why can't browser JavaScript directly read arbitrary files from disk, but Node.js can?

20. Why should readFileSync() be avoided in a running web server?

21. What does fs/promises provide?

22. Why does the path module exist instead of manually building paths with string concatenation?

23. What does path.extname("photo.jpg") return?

24. Are __dirname and __filename automatically available in ES Modules the same way as CommonJS?

25. What does os.platform() return?

26. What is a common use for os.cpus().length?

27. What does os.tmpdir() return?

24. Are dirname and filename automatically available in ES Modules the same way as CommonJS?