Node.js161 questions in the bank

Node.js Quiz: Test Your Node.js Knowledge

Pick how many questions you want, choose a difficulty and go. You'll see why each answer is right or wrong, then you can retry to beat your score.

Questions
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  1. What does REPL stand for?

    • Run Every Program Line
    • Remote Execution Process Layer
    • Repeat Each Previous Line
    • Read-Eval-Print Loop

  2. Which Node versions are recommended for production?

    • Odd-numbered Current releases
    • LTS (Long Term Support) releases
    • Nightly builds
    • Any version

  3. What does process.argv contain?

    • Environment variables
    • The current directory
    • The command-line arguments
    • The Node version

  4. Which runs first?

    • A Promise .then callback
    • A setTimeout callback with 0 ms
    • They run at the same time
    • It's random

  5. What happens if your code runs a long synchronous loop?

    • The event loop is blocked, so no other requests or callbacks can run
    • Node runs it on another thread
    • Node stops the loop automatically
    • Nothing special

  6. What does the node: prefix in import fs from 'node:fs' show?

    • The module comes from npm
    • The module is a CommonJS module
    • The module is optional
    • The module is built into Node.js

  7. How does CommonJS export values?

    • export default
    • module.exports = { ... }
    • exports default
    • return { ... }

  8. What does dynamic import() return?

    • The module directly
    • A string
    • A promise that resolves to the module
    • Nothing

  9. How many default exports can a module have?

    • None
    • One
    • Two
    • Any number

  10. Which file extension always means an ES module, whatever package.json says?

    • .js
    • .cjs
    • .json
    • .mjs

  11. What does npx do?

    • Deletes packages
    • Runs a package's command without a permanent install
    • Publishes a package
    • Updates npm

  12. In version 3.8.2, what does the 8 represent?

    • Major
    • Patch
    • Minor
    • Build

  13. Should package-lock.json be committed to Git?

    • No
    • Only for libraries
    • Only on Windows
    • Yes

  14. Which command checks installed packages for known security problems?

    • npm check
    • npm secure
    • npm verify
    • npm audit

  15. Which scripts can be run without the word run?

    • Any script
    • start and test
    • dev and build
    • None

  16. Which function adds text to the end of a file?

    • appendFile
    • writeFile
    • addFile
    • readFile

  17. What does mkdir with { recursive: true } do?

    • Deletes folders recursively
    • Lists folders
    • Creates any missing parent folders and doesn't fail if the folder exists
    • Copies folders

  18. What does readFile return when no encoding is given?

    • A string
    • An array of lines
    • null
    • A Buffer of bytes

  19. Relative paths in fs calls are resolved against which folder?

    • The current working directory where node was started
    • The script's folder
    • The home folder
    • node_modules

  20. Which is the safer way to read a file that might not exist?

    • Check with existsSync, then read
    • Use writeFile first
    • Use stat in a loop
    • Try to read it and handle the ENOENT error

  21. Which module helps build file paths?

    • fs
    • path
    • os
    • url

  22. What does os.homedir() return?

    • The project folder
    • The temporary folder
    • The current user's home folder
    • The Node install folder

  23. What does path.dirname('/a/b/c.txt') return?

    • c.txt
    • /a
    • /a/b
    • .txt

  24. Which value is the separator for the current operating system?

    • os.EOL
    • path.delimiter
    • os.sep
    • path.sep

  25. What does new URL('https://a.dev/x?q=1').searchParams.get('q') return?

    • 1 (a number)
    • '1' (a string)
    • null
    • q=1

  26. Which method adds a listener that runs every time an event is emitted?

    • once
    • emit
    • on
    • off

  27. How do you remove a listener?

    • emit('remove')
    • delete emitter[name]
    • off(name, sameFunction)
    • on(name, null)

  28. What does await once(emitter, 'ready') give you?

    • The emitter
    • true
    • The listener count
    • An array of the arguments passed to the event

  29. What does a MaxListenersExceededWarning usually point to?

    • Listeners being added repeatedly, which leaks memory
    • A slow listener
    • An error event
    • Too many emitters

  30. Which is a good fit for events rather than a single promise?

    • Reading one file
    • Progress updates that happen many times during an upload
    • A single database query
    • Parsing one JSON string

  31. Where should API keys for a server be stored?

    • In the source code
    • In package.json
    • In environment variables
    • In a comment

  32. How do you load a .env file with Node's built-in support?

    • node --dotenv
    • import '.env'
    • npm env
    • node --env-file=.env app.js

  33. What does process.cwd() return?

    • The current working directory
    • The script's folder
    • The home folder
    • The Node version

  34. What should be committed instead of a real .env file?

    • Nothing
    • A .env.example with variable names and dummy values
    • The production .env
    • A zip of .env

  35. Why is if (process.env.ENABLED) a bug when ENABLED is "false"?

    • "false" is a non-empty string, which is truthy
    • It isn't
    • process.env is undefined
    • It throws an error

  36. In an error-first callback, what is the first argument?

    • The result
    • The file name
    • An error, or null if there was none
    • A promise

  37. How do you handle an error from an awaited promise?

    • With .then only
    • With try/catch around the await
    • Errors can't happen
    • With process.exit

  38. Which method resolves with the first promise to succeed?

    • Promise.any
    • Promise.all
    • Promise.race
    • Promise.allSettled

  39. What does util.promisify do?

    • Makes code faster
    • Converts an error-first callback function into one that returns a promise
    • Creates a timer
    • Catches every error

  40. What happens in modern Node when a rejected promise is never handled?

    • Nothing
    • It's retried
    • An error is reported and the process exits
    • It's logged and ignored forever

  41. Which built-in module creates a web server?

    • node:net only
    • node:web
    • node:http
    • node:server

  42. Which HTTP method is usually used to create a resource?

    • GET
    • DELETE
    • HEAD
    • POST

  43. Which header tells the client that the body is JSON?

    • Accept: application/json
    • Body-Type: json
    • Content-Type: application/json
    • Format: json

  44. Does fetch throw an error when the server responds with 500?

    • No, check response.ok or response.status
    • Yes
    • Only for POST requests
    • Only in Node

  45. What does status 405 mean?

    • The resource moved
    • The method isn't allowed for this URL
    • The server is overloaded
    • Authentication is required

  46. Which method sends JSON with the right Content-Type?

    • res.send
    • res.write
    • res.end
    • res.json

  47. How do you send a 404 with a JSON message?

    • res.json(404, {...})
    • res.status(404).json({ error: 'Not found' })
    • res.send404()
    • res.error(404)

  48. What error appears if a handler sends two responses?

    • Cannot set headers after they are sent
    • 404
    • Unexpected token
    • ECONNRESET

  49. Which response suits a successful DELETE with nothing to return?

    • res.json(null)
    • res.redirect('/')
    • res.status(500)
    • res.sendStatus(204)

  50. What does Express 5 do differently with errors thrown in async route handlers?

    • Ignores them
    • Restarts the server
    • Passes them to the error-handling middleware automatically
    • Returns 200

  51. Where do route parameters appear?

    • req.query
    • req.body
    • req.route
    • req.params

  52. What option lets a nested router read its parent's parameters?

    • strict: true
    • mergeParams: true
    • caseSensitive: true
    • nested: true

  53. How is an optional path segment written in Express 5?

    • /files{/:name}
    • /files/:name?
    • /files/[name]
    • /files/*name?

  54. What's a good way to organise routes in a growing project?

    • One file for every route
    • Everything in app.js
    • One router per feature, mounted under a prefix
    • One router for GET and one for POST

  55. In Express 5, what does a named wildcard like /docs/*path put in req.params.path?

    • A string
    • A number
    • An array of the matched segments
    • Nothing

  56. Which line applies middleware to every request?

    • app.get(fn)
    • app.use(fn)
    • app.all(fn)
    • app.listen(fn)

  57. What does the cors package do?

    • Lets browsers on other domains call your API
    • Compresses responses
    • Logs requests
    • Parses cookies

  58. Which status should authentication middleware send when no valid login is present?

    • 403
    • 404
    • 500
    • 401

  59. How do you apply middleware to just one route?

    • app.use only
    • Put it in package.json
    • It's not possible
    • Pass it before the handler: app.get('/x', check, handler)

  60. How can middleware run code after the response has been sent?

    • By calling next twice
    • By using setTimeout
    • By listening for the response's finish event
    • It can't

  61. Which status code fits a successful DELETE with no body?

    • 204
    • 200
    • 201
    • 404

  62. What should a POST response include besides the new item?

    • A redirect
    • A Location header with the new item's URL
    • The full list
    • Nothing

  63. Why put data logic in a service module instead of in routes?

    • Express requires it
    • It keeps routes thin and lets the logic be tested and reused without HTTP
    • It makes responses faster
    • Services are needed for JSON

  64. What does sort=-price usually mean?

    • Sort by price, highest first
    • Remove the price field
    • Sort by price, lowest first
    • Filter out negative prices

  65. Why version an API with a prefix like /api/v1?

    • It's faster
    • Browsers require it
    • To hide the API
    • Breaking changes can go into v2 while existing clients keep using v1

  66. What type are route parameters and query values in Express?

    • Whatever type they look like
    • Numbers
    • JSON
    • Strings

  67. What does a Zod object schema do with unknown keys by default?

    • Removes them from the parsed result
    • Rejects the data
    • Keeps them
    • Converts them to strings

  68. Which Zod method gives a value when a field is missing?

    • .optional()
    • .nullable()
    • .fill(value)
    • .default(value)

  69. Where should validation happen in an Express app?

    • Deep in the database code
    • At the edge, in the route or a validation middleware, before the data is used
    • Only in the browser
    • After saving

  70. Why is mass assignment, saving req.body directly, dangerous?

    • It's slow
    • JSON can't be saved
    • Clients can set fields they shouldn't, such as a role or a balance
    • It loses data

  71. Which middleware parses HTML form submissions?

    • express.json()
    • express.static()
    • express.urlencoded()
    • express.form()

  72. Which files are safe to cache for a year?

    • index.html
    • API responses
    • Every file
    • Fingerprinted assets like app.3f9a1c.js whose names change with their content

  73. What attack does escaping user content prevent?

    • Cross-site scripting (XSS)
    • SQL injection
    • Denial of service
    • Brute force

  74. How do you render the template views/home.ejs with data?

    • res.send('home', data)
    • res.render('home', data)
    • res.template('home.ejs')
    • res.sendFile('home.ejs')

  75. Can express.static serve files outside its folder for a URL like /../server.js?

    • Yes
    • Only on Windows
    • No, it rejects paths that leave the folder
    • Only for .js files

  76. Which status code should an unexpected server bug produce?

    • 400
    • 404
    • 500
    • 200

  77. How does Express 5 handle an error thrown in an async route?

    • It crashes the server
    • It passes the error to the error-handling middleware
    • It returns 200
    • It ignores it

  78. Why give custom errors a status property?

    • For speed
    • JavaScript requires it
    • To hide the message
    • So the central error handler can choose the right HTTP status

  79. Why throw Error objects instead of strings?

    • Error objects include a stack trace and can be checked with instanceof
    • Strings can't be caught
    • Strings are slower
    • There's no difference

  80. Which errors are worth retrying automatically?

    • Validation errors
    • 404 Not Found
    • Temporary failures such as 503 or a reset connection
    • Syntax errors

  81. Which function creates a readable stream from a file?

    • createReadStream
    • readFile
    • openStream
    • streamFile

  82. What does pipeline do if one of its streams fails?

    • Continues with the others
    • Restarts the stream
    • Nothing
    • Destroys all the streams and rejects with the error

  83. How do you finish writing to a writable stream?

    • close()
    • stop()
    • finish()
    • end()

  84. What does Readable.from(array) do?

    • Turns the array (or any iterable) into a readable stream
    • Copies the array
    • Reads a file
    • Sorts the array

  85. Is an HTTP response object a stream?

    • No
    • Only for files
    • Yes, a writable stream
    • Only with Express

  86. Which built-in module gives Node SQLite support?

    • node:sql
    • node:db
    • node:database
    • node:sqlite

  87. What does run() return after an INSERT?

    • The inserted row
    • true
    • Nothing
    • An object with changes and lastInsertRowid

  88. What's a database migration?

    • Moving to a new server
    • A versioned script that changes the database structure step by step
    • A backup
    • A slow query

  89. What placeholder style does the pg driver use?

    • ?
    • :name only
    • $1, $2 and so on
    • {0}

  90. Why put queries in a repository module?

    • Queries live in one place, are easy to change and can be replaced with fakes in tests
    • SQL only runs there
    • It's faster
    • ORMs require it

  91. Which status code means "not signed in"?

    • 403
    • 404
    • 500
    • 401

  92. What does the Secure cookie flag do?

    • Sends the cookie only over HTTPS
    • Encrypts the cookie
    • Hides it from JavaScript
    • Makes it permanent

  93. Why should password hashing be slow?

    • To save memory
    • To make guessing passwords from a leaked database very expensive
    • Because crypto is slow
    • It shouldn't be

  94. What's an advantage of server-side sessions over JWTs?

    • No storage needed
    • They never expire
    • They can be revoked instantly by deleting the session
    • They work without cookies

  95. Why compare hashes with timingSafeEqual instead of ===?

    • === doesn't work on Buffers
    • It's faster
    • It decrypts the hash
    • It takes the same time however many bytes match, so response times reveal nothing

  96. Where should API keys and database passwords live?

    • In the source code
    • In environment variables or a secret manager
    • In package.json
    • In public/config.js

  97. What does Content-Security-Policy help prevent?

    • SQL injection
    • Brute force attacks
    • Slow queries
    • Cross-site scripting, by limiting where scripts can load from

  98. Which routes most need strict rate limits?

    • Sign-in, sign-up and password reset
    • Static images
    • The home page
    • Health checks

  99. What does npm audit do?

    • Reports installed packages with known vulnerabilities
    • Speeds up installs
    • Removes unused packages
    • Encrypts node_modules

  100. What does the principle of least privilege mean for a Node server?

    • Use as few packages as possible
    • Run with only the permissions it needs, for example as a non-root user with a limited database account
    • Give every user admin rights
    • Disable logging

  101. Which module provides test, describe and it?

    • node:assert
    • node:spec
    • node:check
    • node:test

  102. What does assert.equal use to compare in node:assert/strict?

    • ===
    • ==
    • Object.is only for numbers
    • JSON.stringify

  103. How can a test move time forward without waiting?

    • Enable mock timers and call mock.timers.tick(ms)
    • await sleep
    • Change the system clock
    • It can't

  104. How should an API test start the server?

    • On port 80
    • By running npm start in another terminal
    • It doesn't need a server
    • On port 0, so the system picks any unused port

  105. What should good tests focus on?

    • Private helper functions
    • Observable behaviour: inputs, outputs and errors
    • Line-by-line implementation
    • Only the happy path

  106. Which URL scheme is used for secure WebSockets?

    • https://
    • ws+ssl://
    • wss://
    • sws://

  107. How do you send a message to every connected client with ws?

    • wss.sendAll()
    • socket.broadcast()
    • Loop over wss.clients and send to each open socket
    • It isn't possible

  108. What Content-Type does a Server-Sent Events response use?

    • text/event-stream
    • application/json
    • text/plain
    • application/sse

  109. Why include a type field in WebSocket messages?

    • It's required by the protocol
    • To compress them
    • For security
    • So each side knows how to handle each kind of message

  110. How do several WebSocket servers share messages so every client receives them?

    • They can't
    • Through a shared message channel such as Redis pub/sub
    • By using one port
    • By sending larger messages

  111. Which module provides Worker and parentPort?

    • node:child_process
    • node:worker_threads
    • node:cluster
    • node:os

  112. Why pass command arguments as an array to execFile?

    • They aren't interpreted by a shell, which prevents command injection
    • It's faster
    • Arrays are required by Windows
    • To run in parallel

  113. What does the cluster module do?

    • Groups database rows
    • Creates worker threads
    • Compresses responses
    • Starts several Node processes that share a server port to use more CPU cores

  114. Why use a worker pool rather than a new worker per task?

    • Pools are required
    • Pools share variables
    • Starting workers is slow and uses memory; a pool reuses a fixed set
    • Workers can only run once

  115. Is data passed with postMessage shared or copied between threads by default?

    • Copied
    • Shared
    • Deleted
    • Encrypted

  116. Which method shows an array of objects as a table?

    • console.dir
    • console.table
    • console.grid
    • console.list

  117. What is structured logging?

    • Writing each log entry as data, such as one JSON object per line with fields
    • Logging only errors
    • Logging in a table
    • Logging to separate files

  118. Which flag records a CPU profile?

    • --profile-cpu
    • --inspect-cpu
    • --cpu-prof
    • --trace

  119. What should you do before optimising code for speed?

    • Rewrite it
    • Add more servers
    • Measure where the time actually goes
    • Remove logging

  120. Which tool helps find which objects are filling memory?

    • console.time
    • A heap snapshot in Chrome DevTools
    • npm audit
    • node --watch

  121. Which signal do platforms send to stop a Node process gracefully?

    • SIGKILL
    • SIGHUP
    • SIGTERM
    • SIGSTOP

  122. What does NODE_ENV=production change in Express?

    • Nothing
    • It disables routing
    • It turns on debug logging
    • It enables caching and less detailed error pages

  123. Where should a production Node app write its logs?

    • Standard output, collected by the platform
    • A file inside the container
    • The database
    • Nowhere

  124. What does a CI/CD pipeline usually do before deploying?

    • Nothing
    • Installs dependencies, lints, runs tests and checks for vulnerabilities
    • Deletes the database
    • Asks every developer for approval by email

  125. Why split an Express app into app.js and server.js?

    • Express requires two files
    • It makes responses faster
    • To use two ports
    • Tests and tools can import the app without starting a real server

  126. Which operation creates independent storage for an existing Buffer view?

    • Buffer.from(view)
    • view.subarray(0)
    • view.slice(0)

  127. Why use StringDecoder for chunked UTF-8?

    • It retains incomplete character bytes between chunks
    • It guarantees every network chunk contains complete JSON
    • It changes the socket into a text-only transport

  128. Why reject duplicate page parameters before Number conversion?

    • Different layers might otherwise use different occurrences
    • Number conversion removes all duplicate keys automatically
    • URLSearchParams rejects repeated names during parsing

  129. Which check identifies the complete trusted redirect origin?

    • Compare parsed target.origin with the configured origin
    • Check whether the original string starts with the trusted hostname
    • Search for the trusted hostname anywhere in pathname

  130. What does an HMAC provide for a webhook body?

    • Integrity and authentication for parties sharing the secret
    • Encryption that prevents observers reading the body
    • A guarantee that the event has never been delivered before

  131. Why check hexadecimal shape before Buffer.from?

    • Decoding alone is not a strict signature-format validator
    • Hexadecimal decoding always rejects every malformed character
    • The check converts SHA-256 into a password hashing algorithm

  132. Which result proves only a hostname match?

    • A successful offline checkServerIdentity call
    • A complete verified TLS handshake with a trusted certificate
    • An HTTPS request that verified its chain and hostname

  133. What is the appropriate response to an unknown internal certificate authority?

    • Configure the intended authority as trusted for the client
    • Set rejectUnauthorized to false for every request
    • Ignore the error if the response status would be 200

  134. Which operation can use operating-system sources such as a hosts file?

    • lookup
    • resolveMx
    • resolveTxt

  135. What does querying resolve4 request?

    • A records representing IPv4 addresses
    • Every available DNS record in one combined response
    • The operating system process ID for a hostname

  136. What guarantee does TCP provide to this parser?

    • Ordered bytes within the connection
    • One data event for each sender write
    • Automatic JSON validation for every payload

  137. Which length belongs in the fixture header for café?

    • Its UTF-8 byte length
    • Its JavaScript string length regardless of encoding
    • The number of data events received

  138. Which HTTP length describes a compressed response body?

    • The number of transmitted compressed bytes
    • The original JavaScript string length
    • The number of JSON object properties

  139. Why emit Vary: Accept-Encoding when encodings differ?

    • Caches need to distinguish representations selected by that request header
    • It forces every client to accept Brotli
    • It disables content type validation

  140. What does a timeout delay promise?

    • An eligibility threshold, not an exact execution time
    • An interruption of any currently running JavaScript
    • A guaranteed callback time unaffected by CPU work

  141. How can an async setInterval callback overlap its own work?

    • A later tick can begin while an earlier awaited operation is unfinished
    • await automatically stops future interval ticks
    • Intervals are limited to one invocation for the process lifetime

  142. Why must an unsuccessful response body be consumed or canceled before retrying?

    • It owns stream and connection resources even with an error status
    • fetch always consumes error bodies automatically
    • A canceled body makes POST automatically idempotent

  143. What policy makes retries appropriate for a state-changing request?

    • A documented remote idempotency mechanism and bounded retry rules
    • Any AbortError proves the remote action never started
    • Changing POST to GET inside the client automatically fixes the endpoint

  144. Why await each question before starting the next?

    • It keeps answer ownership and conversation order explicit
    • It converts every answer automatically into a number
    • It hides typed characters from the terminal

  145. Where should readline cleanup normally happen?

    • In finally under the component that owns the interface
    • Only after a valid numeric answer
    • Inside every data callback by destroying process.stdin

  146. What is the purpose of #settings in the main fixture?

    • A private package imports mapping
    • A URL fragment automatically downloaded by Node
    • A public subpath available from every external package

  147. Why test package-name imports rather than only relative source imports?

    • The resolver contract can fail while relative files still work
    • Relative imports always publish the package automatically
    • Package-name tests remove the need to check module formats

  148. Why is a global currentRequestId unsafe during overlapping awaits?

    • Another request can overwrite it before the first resumes
    • await automatically copies every global variable
    • Node forbids all global variables inside servers

  149. Why keep context stores small?

    • Long-lived async work can retain their data beyond the request
    • AsyncLocalStorage rejects stores with more than one property
    • Small stores automatically authenticate request IDs

  150. Which adapter connects a Web readable to a Node pipeline?

    • Readable.fromWeb
    • Readable.toWeb
    • WritableStream.getReader

  151. What does getReader establish?

    • Exclusive reading ownership through a stream lock
    • Automatic unlimited copying for every later consumer
    • A conversion from objects to UTF-8 bytes

  152. Which field supplies the response status in the low-level server?

    • The :status pseudo-header
    • A Connection: status=200 header
    • The session URL fragment

  153. What remains necessary for browser-facing secure HTTP/2?

    • Valid TLS configuration and appropriate protocol negotiation
    • Only changing the content type to application/http2
    • Disabling hostname verification so ALPN can succeed

  154. What does a TypeScript assertion do to untrusted JSON at runtime?

    • It does not validate or convert the value
    • It checks every property against the interface
    • It automatically rejects unknown fields

  155. Which feature is outside default erasable stripping?

    • An enum requiring generated JavaScript
    • A type alias
    • A parameter type annotation

  156. What does ERR_ACCESS_DENIED represent in the main child?

    • The selected resource operation was not granted by the enabled model
    • The file must be missing from the operating system
    • The trusted code has been proven malicious

  157. Why avoid responding to every denial with --allow-fs-read=*?

    • It replaces the narrow intended authority with broad filesystem read access
    • The wildcard limits access only to one extension
    • It gives write access but leaves read access unchanged

  158. Why count actual request bytes as well as inspect Content-Length?

    • The declared length is not the entire enforcement policy and may be absent
    • Every request body always contains exactly one byte per character
    • Content-Length automatically validates every uploaded format

  159. Why not place every accepted upload directly in a public static directory?

    • Acceptance and public download authorization are separate decisions
    • randomUUID automatically grants safe public access
    • A static directory prevents file processing errors

  160. What happens to the main sale calculation after unsubscribe?

    • It still returns the required total without observation
    • It must fail because no monitor authorizes it
    • It waits until another subscriber appears

  161. Why avoid mutating a published message in a subscriber?

    • Other subscribers may observe the same payload object
    • publish clones every message deeply before every callback
    • Mutation automatically makes an event durable
RelaxedNo clock. Read the explanation after each answer.
Timed30 seconds per question. Great for revision.
Exam modeNo feedback until the end, then a full review.

About the Node.js quiz

This Node.js quiz covers every lesson in the course, from running scripts and modules to Express, databases, security and deployment. Many questions show a few lines of Node code and ask what they print or which status code a server returns, because predicting behaviour is the best way to check that you understand it. Others check vocabulary you'll meet in documentation and job interviews, such as "event loop", "middleware", "prepared statement" and "graceful shutdown".

If you're still in the beginner stage, choose Easy and a topic you've just finished, such as modules or the file system. After the intermediate lessons, try Mixed with 10 questions to practise Express, REST and validation together. Save Exam mode for the end of the course: it hides the answers until you finish, so it's an honest check of what you remember.

When you miss a question, read the explanation and revisit the lesson linked in your results. Node mistakes often come from small details: a missing await, forgetting that query values are strings, or middleware that never calls next(). Spotting them in a quiz makes them easy to avoid in real code.

The question bank holds 161 questions drawn from 43 Node.js lessons: 43 easy, 93 medium and 25 hard. Every time you start, the quiz picks a fresh random selection that matches your settings, so retaking it is a good way to practise. After each answer, or at the end in exam mode, you'll see why the right answer is right, and every question you miss links back to the lesson that teaches it.

What the Node.js quiz covers

Beginner

  1. 1Node.js Introduction5 questions
  2. 2Node.js Modules5 questions
  3. 3npm and Packages5 questions
  4. 4Node.js File System5 questions
  5. 5Node.js path and os5 questions
  6. 6Node.js Events5 questions
  7. 7Node.js process and Environment Variables5 questions
  8. 8Node.js Async Patterns5 questions

Intermediate

  1. 9Node.js HTTP Server5 questions
  2. 10Express Basics5 questions
  3. 11Express Routing5 questions
  4. 12Express Middleware5 questions
  5. 13Building a REST API5 questions
  6. 14Input Validation5 questions
  7. 15Static Files and Templates5 questions
  8. 16Error Handling5 questions
  9. 17Node.js Streams5 questions

Advanced

  1. 18Databases with Node.js5 questions
  2. 19Authentication5 questions
  3. 20Node.js Security5 questions
  4. 21Testing Node.js5 questions
  5. 22WebSockets and Real-Time5 questions
  6. 23Child Processes and Worker Threads5 questions
  7. 24Debugging and Performance5 questions
  8. 25Deploying Node.js5 questions

Runtime and network references

  1. 26Node.js Buffers and UTF-82 questions
  2. 27Node.js URL and URLSearchParams2 questions
  3. 28Node.js Integrity and Webhook HMAC2 questions
  4. 29Node.js HTTPS and TLS Verification2 questions
  5. 30Node.js DNS Resolution2 questions
  6. 31Node.js TCP Message Framing2 questions
  7. 32Node.js Compression Formats and HTTP2 questions
  8. 33Node.js Timers and Microtasks2 questions
  9. 34Node.js Fetch Bodies and Cancellation2 questions

Tools and application boundaries

  1. 35Node.js Interactive Readline CLIs2 questions
  2. 36Node.js Package Exports and Imports2 questions
  3. 37Node.js AsyncLocalStorage Request Context2 questions
  4. 38Node.js Web Streams Interoperability2 questions
  5. 39Node.js HTTP/2 Sessions and Streams2 questions
  6. 40Node.js Native TypeScript Type Stripping2 questions
  7. 41Node.js Permission Model2 questions
  8. 42Node.js Bounded File Uploads2 questions
  9. 43Node.js Diagnostics Channel Instrumentation2 questions
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