Node.js · Theory

http2session.ping([payload, ]callback) function in Node.js

Theory

472/723

http2session.ping([payload, ]callback) function in Node.js

http2session.ping([payload, ]callback) function (node js) is a Node.js topic. In plain words you use it for read notes.txt in a script. Don’t start with a slogan — start with that picture.

Smallest example: (err, data) => …. Type it, run it, and say what you see. If you can do that from memory, you know http2session.ping([payload, ]callback) function (node js).

From the example next to this theory — http2session.

Trap — callback hell, no error-first. Fix that before you talk about advanced Node.js.

Viva: what is http2session.ping([payload, ]callback) function (node js)? Then show (err, data) => …. Then name the trap.

Diagram

  request
      │
      ▼
  event loop
      │ I/O done
      ▼
  response

Exam tip

What is http2session.ping([payload, ]callback) function (node js)? Show this: (err, data) => …. Trap: callback hell, no error-first.

Example

function wait(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

(async () => {
  console.log("start");
  await wait(50);
  console.log("done");
})();

http2session.ping([payload, ]callback) function in Node.js — async/await sits on Promises — cleaner than nested callbacks.

Short notes

Defhttp2session.ping([payload, ]callback) function (node js) — read notes.txt in a script.
Rule(err, data) => …
Trapcallback hell, no error-first
Usea script

Node.js · Theory

http2session.ping([payload, ]callback) function in Node.js

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Theory

472/723

http2session.ping([payload, ]callback) function in Node.js

http2session.ping([payload, ]callback) function (node js) is a Node.js topic. In plain words you use it for read notes.txt in a script. Don’t start with a slogan — start with that picture.

Smallest example: (err, data) => …. Type it, run it, and say what you see. If you can do that from memory, you know http2session.ping([payload, ]callback) function (node js).

From the example next to this theory — http2session.

Trap — callback hell, no error-first. Fix that before you talk about advanced Node.js.

Viva: what is http2session.ping([payload, ]callback) function (node js)? Then show (err, data) => …. Then name the trap.

Diagram

  request
      │
      ▼
  event loop
      │ I/O done
      ▼
  response

Exam tip

What is http2session.ping([payload, ]callback) function (node js)? Show this: (err, data) => …. Trap: callback hell, no error-first.

Example

function wait(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

(async () => {
  console.log("start");
  await wait(50);
  console.log("done");
})();

http2session.ping([payload, ]callback) function in Node.js — async/await sits on Promises — cleaner than nested callbacks.

Short notes

Defhttp2session.ping([payload, ]callback) function (node js) — read notes.txt in a script.
Rule(err, data) => …
Trapcallback hell, no error-first
Usea script

http2session.ping([payload, ]callback) function in Node.js

Example

Short notes

Questions

http2session.ping([payload, ]callback) function in Node.js

Example

Short notes

Questions