MikeDigitize

function makeIndex() {
    return Math.random().toString(12).substring(2, 12);
}

function Awesome() {
    Object.defineProperty(this, 'index', {
        writable: false,
        configurable: false,
        value: makeIndex()
  });

MikeDigitize

// Write a wrapper around the Web Animations API

// takes a HTML element upon creation

// constructor exposes the HTML element, a `keyframe` array of keyframe objects and a `config` object

// the `keyframe` array has a minimum length of 2 (animation start and end), can't start an animation unless satisfied
// each object in the `keyframe` array has a CSS property and value with an optional `offset` property (between 0 - 1, for keyframe %)

// the config object specifies duration, easing and iterations

MikeDigitize

<style>
.box {
  display: flex;
  align-items: center;
  justify-content: center;
  margin: auto;
}

.red {
  width: 300px;

MikeDigitize

<span class="ball"></span>
<span class="ball"></span>
<span class="ball"></span>
<span class="ball"></span>
<span class="ball"></span>

.ball {
  width: 20px;
  height: 20px;
  border-radius: 50%;

MikeDigitize

function getNumberOfPermutations(input) {

    if (!input.length) {
        return 0;
    }

    let { length } = input;
    let dividend = getFactorial(length);
    let divisor = 0