Node.js? ???, ??? ???? ? ??? ??? ??? ??? ??? ??? ??? ????. ?? ?? ?? ???? ???? ?? ??? ????? ??? ??? ??? ???? ?? ?? ??? ????? ??? ? ????. ? ????? ??? ??? ?? ??? ????, 6??? ????, ??? ?? ??? ???? ??? ?? ?????.

Node.js? ??? ?? ??

Node.js? ??? ??? ??? ??? ????? ?? ??? ??? ?????. 6??? ?????.

Node.js? ??? ?? ??

??? ??? ??? ??? ???? ???????. I/O ?? ???? ?? ??? ??? ??? ??? ??? ?? ??? ?? ??? ????? ?? ??? ?????. ??? ??? ?? Node.js? ?? ???? ???? ?? ?? ??? ??? ? ?? ??????? ?? ??? ??? ? ????.

??? ??? 6??

??? ??? 6?? ?? ??? ???? ?? ???? ?????. ? ???? ?? ??? ??? ?? ?? ??? ?????.

1. ??? ??

? ????? setTimeout ? setInterval? ?? ??? ??? ?????. ??? ?? ??? ??? ?? ?? ??? ???? ?????.

?:

setTimeout(() => {
  console.log('Executed after 1 second.');
}, 1000);
console.log('Timer scheduled.');

??:

Timer scheduled.
Executed after 1 second.

?? ??? 1000ms?? ?? ??? ?? ?? ??? ?? setTimeout? ?????.

setInterval? ?

let count = 0;
const intervalId = setInterval(() => {
  console.log(`Interval executed: ${++count}`);
  if (count === 3) clearInterval(intervalId);
}, 500);

2. ?? ?? ??

? ???? ??? ??? ?? ???? ??? I/O ??? ?????. ??? ??? ?? ? ??? I/O ??? ?????.

?:

const fs = require('fs');
fs.readFile('file.txt', (err, data) => {
  if (err) console.error(err);
  else console.log(data.toString());
});

??:

Read operation scheduled.
File content:<contents of example.txt>

3. ??, ?? ??

? ??? Node.js?? ?? ?? ???? ?? ???? ???? ?? ????? ?????. ? ??? ?? ??????? ??? ?? ?? ??? ?? ??? ???? ?? ??? ?? ??? ?????? ? ????.

TCP ?? ?? ??(?? ??)

const net = require('net');
const server = net.createServer((socket) => {
  socket.end('Connection closed.');
});

server.listen(8080, () => {
  console.log('Server listening on port 8080.');
});

?? ????? ? ??? ??????. ??? ???? ???? ??? ???? ?? ??? ?????.

4. ?? ??

?? ?? ?? ??? ??? ??? I/O ???? ???? ?? ??? ?????. ?? ?? ???? ??? ? ???? ????? ???? ??? ??? ? ??? ? ??? ?????.

setTimeout(() => {
  console.log('Executed after 1 second.');
}, 1000);
console.log('Timer scheduled.');

??? ??? HTTP ??? ???? ?? ??? ?????. ??? ???? ?? ??? ???? ??? ????.

5. ?? ??

check ????? setImmediate? ??? ??? ?????. ??? ??? ?? ?? I/O ??? ??? ??? ???? ?? ?? ?? ?????.

?:

Timer scheduled.
Executed after 1 second.

??:

let count = 0;
const intervalId = setInterval(() => {
  console.log(`Interval executed: ${++count}`);
  if (count === 3) clearInterval(intervalId);
}, 500);

6. ?? ?? ??

? ????? ?? ??? ?????. ?? ?? socket.on('close') ? ???? ?? ??? ??? ??? ???? ?????.

const fs = require('fs');
fs.readFile('file.txt', (err, data) => {
  if (err) console.error(err);
  else console.log(data.toString());
});

??:

Read operation scheduled.
File content:<contents of example.txt>

????? ??? ???? ?? ?? ???? ??.on('close') ??? ?????.

??? ?? ??

??? ??? ??? ??? ????? ????? ?????? ??? ???? ??? ??? ? ????. ?? ???? ??? ???? ?? ???? ?? ???? ?? ??? ???? ????. ?? ?? ??? ???? ??????? ???? ?? ? ????.

?? ????? CPU ???? ??(?: ??? ??)? ???? ??? ??? ?????. ??? ???? ???? ??? ???? ??? ??? ????.

??? ?? ?? ??

const net = require('net');
const server = net.createServer((socket) => {
  socket.end('Connection closed.');
});

server.listen(8080, () => {
  console.log('Server listening on port 8080.');
});

??:

const http = require('http');

const server = http.createServer((req, res) => {
  res.end('Hello from server!');
});

server.listen(3000, () => {
  console.log('Server running on http://localhost:3000');
});

? ???? 5? ?? ?? ?? ?? ?? ?? ??? ? ???? ??????? ???? ?? ???.

???: ??? ??? ??

setImmediate(() => {
  console.log('Executed in check phase.');
});

setTimeout(() => {
  console.log('Executed in timers phase.');
}, 0);

console.log('Main code executed.');

??:

Main code executed.
Executed in check phase.
Executed in timers phase.

??? ?? ??? ??? ????? ????? ??? ??? ?? ??? ???? ??? ? ????.

??? ?? ??? ???? ??

CPU ??? ??? ??? ??? ??:

Node.js? ??? ??, ??? ?? ??? ??? ?? ??? ???? ?? ??? ??? ??? ?????. ?? ?? ??? ??? ??? ???? ??? ???? ??? ????? ? ????.

??? ???? ?:

setTimeout(() => {
  console.log('Executed after 1 second.');
}, 1000);
console.log('Timer scheduled.');

? ??? ?? ??? ???:

??? ?? ?? setImmediate? ???? ??? ??? ? ?? ??? ???? ????.

?:

Timer scheduled.
Executed after 1 second.

??

??? ??? ??? ??? ????? ???? Node.js? ?? ?? ?????. ???, ?? ?? ??, ?? ? ??, ??, ?? ? ?? ?? ? 6??? ?????? ???? ???? ???? ??? ??? ??? ? ????. ??? ??? ???? ?? ??? ??? ???? ?? ???? ?? ?????. ??? ???? ?? ??? ???? ??????? ??? ???? ??? ? ????. ??? ??? ????? ?? ???? ??? ??? Node.js ??????? ??? ? ????.

? ??? Node.js? ??? ??: ??? ?? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!