Mohan mohan-mu

What is new in the ES2021 edition of “JavaScript for impatient programmers”?

Free to read online: exploringjs.com/impatient-js/

The exercises now run as native ESM modules on Node.js. Previously, they were run via the esm package.
Material on new ES2021 features:
- String.prototype.replaceAll()
- Promise.any()
- Logical assignment operators
Underscores (_) as separators in number literals and bigint literals

Articles for the New JS Dev

A list of the gists that have proved most useful to new JS devs on GitHub.

How to create an HTTPS certificate for localhost domains

This focuses on generating the certificates for loading local virtual hosts hosted on your computer, for development only.

Do not use self-signed certificates in production ! For online certificates, use Let's Encrypt instead (tutorial).

1. Get your IP Address

echo `ifconfig $(netstat -nr | grep -e default -e "^0\.0\.0\.0" | head -1 | awk '{print $NF}') | grep -e "inet " | sed -e 's/.*inet //' -e 's/ .*//' -e 's/.*\://'`

2. Modify your hosts file

Module 1

Semantic markup
HTML standards mode and quirks mode
HTML fundamentals
- Classes and IDs
CSS fundamentals
- Selectors
- Resets and normalizers
- The box model

	const ids = [];
	const data = ['139', '576'];

	data.map(id => ids.push(Math.max(...id)));

	// What's the output?
	console.log(ids);

	HTML
	- Semantic HTML
	- Event delegation
	- Accessibility / ARIA

	CSS
	- Specificity
	- Pseudo-elements
	- Pseudo-selectors
	- Combinators

	import { AbstractControl, FormArray, FormGroup } from '@angular/forms';
	import { map, toPairs, fromPairs, differenceWith, isEqual, isNull, isUndefined } from 'lodash';
	import { Observable, OperatorFunction, defer, empty, of, merge, pipe } from 'rxjs';
	import { distinctUntilChanged, filter, map, shareReplay, pairwise } from 'rxjs/operators';

	/**
	* Convenience RxJS operator that filters out undefined & null and modifies the downstream type
	* appropriately.
	*/
	export function exists<T>(): OperatorFunction<T \| undefined \| null, T> {

	import React, { Component } from 'react';

	import { withRouter } from 'react-router-dom'; // <--- import `withRouter`. We will use this in the bottom of our file.

	class ContactForm extends Component {

	submitForm (e) {
	e.preventDefault()
	this.props.history.push('/thank-you'); // <--- The page you want to redirect your user to.
	}

	// for browser using, this code requires javascript 1.7+

	var arr = [
	{ foo: 'bar', lorem: 'ipsum' },
	{ foo: 'bar', lorem: 'ipsum' },
	{ foo: 'bar', lorem: 'ipsum dolor sit amet' }
	];

	arr = arr.map(JSON.stringify).reverse() // convert to JSON string the array content, then reverse it (to check from end to begining)
	.filter(function(item, index, arr){ return arr.indexOf(item, index + 1) === -1; }) // check if there is any occurence of the item in whole array