Node.js · Theory

fs.readdir() method

← All stacks

Theory

103/723

fs.readdir() method

fs.readdir() method sits in an upload job. Kabir’s job is read a big CSV. Write that first.

Keep fs.readdir() method small. Kabir should finish read a big CSV in a few lines, not a 40-line dump.

Skip fs.readdir() method and loading the whole file into RAM shows up in an upload job.

fs.readdir() method shows up in an upload job. Name read a big CSV, not “a real-world scenario”.

Don’t do this with fs.readdir() method — loading the whole file into RAM. Interviewers spot it in ten seconds.

Place fs.readdir() method next to nearby Node.js work — createReadStream is the link.

Close fs.readdir() method with — “If I skip it, read a big CSV goes wrong like this: loading the whole file into RAM.”

Exam tip

Say fs.readdir() method in one breath, then createReadStream, then loading the whole file into RAM.

Example

const fs = require("fs");
const path = require("path");

const file = path.join(__dirname || ".", "demo.txt");
fs.writeFileSync(file, "hello node\n");
const text = fs.readFileSync(file, "utf8");
console.log(text.trim());
fs.unlinkSync(file);

fs.readdir() method — fs reads/writes files. Prefer promises/async APIs in real apps.

Short notes

Deffs.readdir() method — Kabir uses it for read a big CSV in an upload job.
Rulefs.readdir() method → createReadStream.
Rememberfs.readdir() method + an Express route (an upload job).
Usefs.readdir() method in an upload job (read a big CSV).
Trapfs.readdir() method — loading the whole file into RAM.
Exfs.readdir() method → read a big CSV.

const fs = require("fs"); const path = require("path"); const file = path.join(__dirname || ".", "demo.txt"); fs.writeFileSync(file, "hello node\n"); const text = fs.readFileSync(file, "utf8"); console.log(text.trim()); fs.unlinkSync(file);

fs.readdir() method

Example

Short notes

Questions

fs.readdir() method

Example

Short notes

Questions