thawkin3

const user = {
  firstName: 'John',
  lastName: 'Doe',
  address: {
    street: '123 Anywhere Lane',
    city: 'Some Town',
    state: 'NY',
    zip: 12345,
  },
}

thawkin3

const biggestNumber = Number.MAX_SAFE_INTEGER // 9007199254740991

const incorrectLargerNumber = biggestNumber + 10
// should be: 9007199254741001
// actually stored as: 9007199254741000

thawkin3

const biggestNumber = BigInt(Number.MAX_SAFE_INTEGER) // 9007199254740991n

const correctLargerNumber = biggestNumber + 10n
// should be: 9007199254741001n
// actually stored as: 9007199254741001n

thawkin3

const useCoolFeature1 = true
const useCoolFeature2 = false
const useCoolFeature3 = undefined
const useCoolFeature4 = null

const getUserFeaturePreference = (featurePreference) => {
  return featurePreference ?? true
}

getUserFeaturePreference(useCoolFeature1) // true

thawkin3

import { exportPdf } from './pdf-download.js'

const exportPdfButton = document.querySelector('.exportPdfButton')
exportPdfButton.addEventListener('click', exportPdf)

// this code is short, but the 'pdf-download.js' module is loaded on page load rather than when the button is clicked

thawkin3

const exportPdfButton = document.querySelector('.exportPdfButton')

exportPdfButton.addEventListener('click', () => {
  import('./pdf-download.js')
    .then(module => {
      // call some exported method in the module
      module.exportPdf()
    })
    .catch(err => {
      // handle the error if the module fails to load

thawkin3

// promises 1-3 all will be resolved
const promise1 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 1 resolved!'), 100))
const promise2 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 2 resolved!'), 200))
const promise3 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 3 resolved!'), 300))

// promise 4 and 6 will be resolved, but promise 5 will be rejected
const promise4 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 4 resolved!'), 1100))
const promise5 = new Promise((resolve, reject) => setTimeout(() => reject('promise 5 rejected!'), 1200))
const promise6 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 6 resolved!'), 1300))

thawkin3

// promises 1-3 all will be resolved
const promise1 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 1 resolved!'), 100))
const promise2 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 2 resolved!'), 200))
const promise3 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 3 resolved!'), 300))

// promise 4 and 6 will be resolved, but promise 5 will be rejected
const promise4 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 4 resolved!'), 1100))
const promise5 = new Promise((resolve, reject) => setTimeout(() => reject('promise 5 rejected!'), 1200))
const promise6 = new Promise((resolve, reject) => setTimeout(() => resolve('promise 6 resolved!'), 1300))

thawkin3

const regexp = /t(e)(st(\d?))/
const regexpWithGlobalFlag = /t(e)(st(\d?))/g
const str = 'test1test2'

// Using `RegExp.prototype.exec()`
const matchFromExec = regexp.exec(str)
console.log(matchFromExec)
// ["test1", "e", "st1", "1", index: 0, input: "test1test2", groups: undefined]

// Using `String.prototype.match()` on a regular expression WITHOUT a global flag returns the capture groups

thawkin3

appState.doesPreferKilograms = JSON.parse(doesPreferKilograms ?? 'true')