Alex Rice ricealexander

I'm going to go over a quick overview of Regular Expressions. I'll try to make the syntax fast, because using them is the fun stuff.

We'll be working with https://regex101.com

What Are RegEx?

RegEx stands for Regular Expression. A Regular Expression is a pattern-matching scheme. We use it to determine whether a string follows certain patterns. We'll often see these used to validate form input, and Single Page Applications may use them to compare the URL with patterns tell it what pages to serve.

(1.) Which of the following are valid arrays (Answer all that apply)

const A = ["Harder", "Better", "Faster", "Stronger"];
const B = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89];
const C = [
  "Urban Chestnut",
  2009,
  "4Hands",
 2011,

	// CSS Color Names
	// Compiled by @bobspace

	// Updates by @ricealexander
	// added Rebecca Purple
	// associates color names with their hex values
	// random color and locating a color in the array by its name

	const colorValues = [
	{hex: "#F0F8FF", name: "AliceBlue"},

	// Inspired by @kokokonotsu
	/// https://github.com/kokokonotsu/Cells-and-Grids

	const
	gridContainer = 'body', // selector for our HTML grid
	columnCount = 26, // number of columns
	rowCount = 20; // number of rows


	// Generate the grid

	:root {
	--system-sans-serif:
	system-ui, /* detect system font automatically */
	-apple-system, /* Safari (Mac OS X and iOS) and Older Mac OS X */
	BlinkMacSystemFont, /* Chrome<56 (Mac OS X) */
	"Segoe UI", /* Windows and Windows Phone */
	"Roboto", /* Android and Chrome OS */
	"Oxygen", /* KDE - Linux environment */
	"Ubuntu", /* Ubuntu - Linux distribution */
	"Cantarell", /* GNOME - Linux environment */

	.countdown-container {
	font-size: 1rem;
	text-align: center;
	}
	.countdown-group {
	display: inline-block;
	margin: 0 1em;
	}
	.countdown-tile {
	border-bottom: 2px solid;

	const arr1 = ["a","b","c"];
	const arr2 = ["d","e","f"];
	const arr3 = ["g","h","i"];


	// Array.prototype.concat()
	const arrayConcat = arr1.concat(arr2).concat(arr3);

	// Array.prototype.push() + spread operator
	const arrayPush = [];

	// Stylesheet dependency builds custom stylesheets
	function Stylesheet(id) {
	this.sheet = id;
	document.head.insertAdjacentHTML("beforeend", '<style id="'+ this.sheet +'"></style>');

	this.add = function(rules) {
	document.getElementById(this.sheet).insertAdjacentText("beforeend", rules);
	}
	};

	// As a thought experiment, what is he shortest bit of code that
	// can generate an array of numbers from 1 to 100?

	// Object.keys
	/// when applied to a string, Object.keys returns an array of
	/// 0 to the string's length - 1
	Object.keys(' '.repeat(100)).map(v => Number(v) + 1)
	Object.keys(' '.repeat(100)).map(v => +v + 1)

	// Array.from

	// deepCopy from
	// https://stackoverflow.com/questions/38416020/deep-copy-in-es6-using-the-spread-syntax#answer-53771927


	function tidyCopy(obj) {
	if(typeof obj !== 'object' \|\| obj === null) {
	return obj;
	}

	if(obj instanceof Date) {