75 verified Backend Nodejs Stdlib Http interview questions — solve with answers, learn from explanations, test yourself in a real simulation.
Try the real simulation →path.sep?\\/✓:.path.sep is the platform-specific path segment separator: / on POSIX, \ on Windows. Code that hardcodes separators instead of using path.sep/path.join breaks across platforms.const buf = Buffer.from('hello');
console.log(Buffer.isBuffer(buf));
console.log(Buffer.isBuffer('hello'));true then false✓false then truetrue then truefalse then falseBuffer.isBuffer() only returns true for actual Buffer instances. A plain string is not a Buffer, so the second call returns false.node app.js foo, what does process.argv[0] represent?foo)app.js)nodeprocess.argv[0] is the executable path (node), argv[1] is the script path, and argv[2] onward are the actual CLI arguments passed by the user.const fs = require('fs');
console.log(fs.existsSync('/definitely/not/here/xyz'));trueErrorfalse✓undefinedfs.existsSync() never throws for a missing path — it simply returns false. It only throws for genuinely invalid arguments (e.g. wrong type).path.parse('/home/user/file.txt') returns an object with which keys?root, dir, base, ext, name✓root, dir, file, extensiondirname, basename, extnamepath, ext, namepath.parse() returns { root, dir, base, ext, name }. base is the full filename (file.txt), name is the filename without extension (file).const http = require('http');
const server = http.createServer((req, res) => {
console.log(req.method);
res.end('ok');
});GET request. What does req.method log?'GET'✓undefined until res.end is called'get' (lowercase)req is an http.IncomingMessage; its method property holds the HTTP verb exactly as it appeared on the wire, e.g. 'GET', 'POST' — Node doesn't uppercase or otherwise normalize it. Here the client sent GET, so req.method === 'GET'.Test yourself against the 3300-question Backend bank.
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