rauschma

Cheat sheet: Arrays

JavaScript Arrays are a very flexible data structure and used as lists, stacks, queues, tuples (e.g. pairs), etc. Some

Using Arrays

Creating Arrays, reading and writing elements:

vinzdef

const server = require('./server.js')
const numCPUs = require('os').cpus().length
const cluster = require('cluster')

function makeCluster() {
  return new Promise((resolve, reject) => {
    if (cluster.isMaster) {
      for (let i = 0; i < numCPUs; i++) {
        cluster.fork()
      }

eneko

$ curl --help
Usage: curl [options...] <url>
     --abstract-unix-socket <path> Connect via abstract Unix domain socket
     --alt-svc <file name> Enable alt-svc with this cache file
     --anyauth       Pick any authentication method
 -a, --append        Append to target file when uploading
     --basic         Use HTTP Basic Authentication
     --cacert <file> CA certificate to verify peer against
     --capath <dir>  CA directory to verify peer against
 -E, --cert <certificate[:password]> Client certificate file and password

sandeepraju

#!/bin/bash
# file: ttfb.sh
# curl command to check the time to first byte
# ** usage **
# 1. ./ttfb.sh "https://google.com"
# 2. seq 10 | xargs -Iz ./ttfb.sh "https://google.com"

curl -o /dev/null \
     -H 'Cache-Control: no-cache' \
     -s \

lastguest

function asyncLoadCSS (css_href) {
  var css_link = function () {
      var h = document.getElementsByTagName('head')[0]
      var l = document.createElement('link')
      l.rel = 'stylesheet'
      l.href = css_href
      h.parentNode.insertBefore(l, h)
    }, RAF = requestAnimationFrame || mozRequestAnimationFrame
      || webkitRequestAnimationFrame || msRequestAnimationFrame
  if (RAF) RAF(css_link); else window.addEventListener('load', css_link)

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

kopiro

server {
	server_name youtube.flerovio.dev;

	location @404 {
		return 302 /sq$request_uri;
	}

	error_page 404 = @404;

	location ~ /sq/(.+) {

sebmarkbage

import { Component } from "React";

export var Enhance = ComposedComponent => class extends Component {
  constructor() {
    this.state = { data: null };
  }
  componentDidMount() {
    this.setState({ data: 'Hello' });
  }
  render() {

ericelliott

Essential JavaScript Links

I no longer mantain this list. There are lots of other very comprehensive JavaScript link lists out there. Please see those, instead (Google "awesome JavaScript" for a start).

kopiro

<style>
	#cookiebar {
		background: #000;
		color: #fff;
		text-align: center;
		min-height: 40px;
		padding: 6px;
		position: fixed;
		bottom: 0;
		left: 0;