NodeJS Core Modules Quiz

To pass the quiz, you must correctly answer at least 18 of the 20 questions below. # --quizzes-- ## --quiz-- ### --question-- #### --text-- Which `fs` method adds content to an existing file without overwriting it? #### --distractors-- `writeFile()` --- `readFile()` --- `unlink()` #### --answer-- `appendFile()` ### --question-- #### --text-- What happens when you use synchronous methods from the `fs` module? #### --distractors-- They delete existing files automatically. --- They run faster than asynchronous ones in all cases. --- They return Promises by default. #### --answer-- They block the program until the operation finishes. ### --question-- #### --text-- What does the `utf8` parameter do in `fs.readFile()`? #### --distractors-- It prevents errors from being thrown. --- It changes the file’s extension. --- It compresses large files. #### --answer-- It tells Node to return a readable string instead of a buffer. ### --question-- #### --text-- Which `Buffer` method creates a new buffer filled with zeros? #### --distractors-- `Buffer.from()` --- `Buffer.concat()` --- `Buffer.byteLength()` #### --answer-- `Buffer.alloc()` ### --question-- #### --text-- What does `Buffer.toString()` do? #### --distractors-- Converts a buffer into binary code. --- Clears the contents of a buffer. --- Shows buffer byte length. #### --answer-- Converts buffer contents into a readable string. ### --question-- #### --text-- Which `crypto` feature requires a private key to generate a signature? #### --distractors-- `createHash()` --- `createCipheriv()` --- `randomBytes()` #### --answer-- `sign()` ### --question-- #### --text-- Why should you avoid writing your own crypto algorithms directly? #### --distractors-- It is illegal in Node.js applications. --- Node.js does not support encryption. --- JavaScript cannot compute hashes. #### --answer-- It can be unsafe without well-tested libraries. ### --question-- #### --text-- What `crypto` method is recommended for generating secure random tokens instead of `Math.random()`? #### --distractors-- `randomInt()` --- `createHmac()` --- `createCipheriv()` #### --answer-- `randomBytes()` ### --question-- #### --text-- Which OS module method returns the CPU architecture? #### --distractors-- `os.cpus()` --- `os.platform()` --- `os.version()` #### --answer-- `os.arch()` ### --question-- #### --text-- What does `os.userInfo()` return? #### --distractors-- Only the username. --- Only the device IP address. --- Only the logged-in user’s ID. #### --answer-- Information about the current system user. ### --question-- #### --text-- Which `path` method joins segments and normalizes extra slashes? #### --distractors-- `path.resolve()` --- `path.extname()` --- `path.dirname()` #### --answer-- `path.join()` ### --question-- #### --text-- Which `path` method produces an absolute path based on the current working directory? #### --distractors-- `path.extname()` --- `path.format()` --- `path.parse()` #### --answer-- `path.resolve()` ### --question-- #### --text-- What does the global variable `__dirname` represent? #### --distractors-- The name of the user running Node. --- The current file’s extension. --- A relative folder path starting with `./`. #### --answer-- The absolute path of the directory containing the current file. ### --question-- #### --text-- Which process property contains environment variables like `NODE_ENV`? #### --distractors-- `process.cwd` --- `process.version` --- `process.platform` #### --answer-- `process.env` ### --question-- #### --text-- What does the `process.on("exit")` event do? #### --distractors-- It restarts the Node application. --- It sends an `exit` signal to child processes. --- It clears the event loop queue. #### --answer-- Executes code right before the Node process finishes. ### --question-- #### --text-- Which stream type can both read and write data but does not transform it? #### --distractors-- Readable stream --- Transform stream --- Writable stream #### --answer-- Duplex stream ### --question-- #### --text-- What is required to implement reading and writing of large files efficiently? #### --distractors-- Using only `Buffer.alloc()` --- Importing the `crypto` module --- Saving the entire file in memory first #### --answer-- Using streams to process data in chunks ### --question-- #### --text-- Which method links a readable stream to a writable stream? #### --distractors-- `pipeTo()` --- `connect()` --- `streamWrite()` #### --answer-- `pipe()` ### --question-- #### --text-- What stream event indicates there is no more data to write? #### --distractors-- `close` --- `drain` --- `end` #### --answer-- `finish` ### --question-- #### --text-- What is logged if you print a chunk from a readable stream without `toString()`? #### --distractors-- Plain text content --- The process PID --- Operating system name #### --answer-- A buffer object with binary data