lakenen

function isAnimatedGif(src, cb) {
	var request = new XMLHttpRequest();
	request.open('GET', src, true);
	request.responseType = 'arraybuffer';
	request.addEventListener('load', function () {
		var arr = new Uint8Array(request.response),
			i, len, length = arr.length, frames = 0;
			
		// make sure it's a gif (GIF8)
		if (arr[0] !== 0x47 || arr[1] !== 0x49 || 

codedokode

Простые задачи на яваскрипт

Пропустить теорию и перейти прямо к задачам

Ссылка на учебник: http://learn.javascript.ru

Сразу расскажу про несколько особенностей яваскрипта, о которых может быть не написано (или мало написано) в учебниках, но которые стоит понимать:

Версии яваскрипта

ljharb

Array Iteration

https://gist.github.com/ljharb/58faf1cfcb4e6808f74aae4ef7944cff

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it mu

Shramkoweb

const express = require('express');
const app = express();
const cors = require('cors');
const socket = require('socket.io');

const port = 8888;

app.use(cors());

const chanels = new Map([