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Streams

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Streams

If you can teach Streams using read a big CSV, you know it. If you only know the heading, you don’t.

Streams order — meaning → createReadStream → one limit. Dumping ten features helps nobody.

Skip Streams and loading the whole file into RAM shows up in an upload job.

Use Streams when read a big CSV must stay clear. If a simpler Node.js step works, use that instead.

Streams trap — loading the whole file into RAM. Amit loses marks for that every viva.

Place Streams next to nearby Node.js work — createReadStream is the link.

Viva for Streams — what it is → createReadStream → the mistake (loading the whole file into RAM).

Exam tip

Board: read a big CSV. Dry-run Streams. Name the trap: loading the whole file into RAM.

Example

// Streams
const users = [
  { id: 1, name: "Asha" },
  { id: 2, name: "Ravi" },
];

function findUser(id) {
  return users.find((u) => u.id === id) ?? null;
}

console.log(findUser(2));
console.log(users.map((u) => u.name));

Streams: find user 2, then list names. Say both prints.

Short notes

DefStreams — Amit uses it for read a big CSV in an upload job.
RuleStreams → createReadStream.
RememberStreams + an Express route (an upload job).
UseStreams in an upload job (read a big CSV).
TrapStreams — loading the whole file into RAM.
ExStreams → read a big CSV.

// Streams const users = [ { id: 1, name: "Asha" }, { id: 2, name: "Ravi" }, ]; function findUser(id) { return users.find((u) => u.id === id) ?? null; } console.log(findUser(2)); console.log(users.map((u) => u.name));

Streams

Example

Short notes

Questions

Streams

Example

Short notes

Questions