danielkhoo / toolbox

Doraemon pouch of hacks, tricks, snippets

Toolbox

Doraemon pouch of snippets, tricks and hacks

JS

Falsy

// falsy: false,undefined,null,0,NaN,''
// not falsy: {}, [],'0','false',-1

Shorter ternaries

x ? x : y  => x || y 
x ? false : true  =>  !x
x ? true : false  =>  !!x

Array methods

const people = [
  {
    id:1,
    name:'alice',
    job:'engineer'
  },
  {
    id:2,
    name:'bob',
    job:'engineer'
  },
  {
    id:3,
    name:'charlie',
    job:'doctor'
  }
]
people.some(p=>p.id===1) //true
people.every(p=>p.job==='doctor') //true
people.find(p=>p.job==='engineer')// {alice}
people.filter(p=>p.name==='engineer')// [{alice},{bob}]

Sort by attribute

people.sort((a,b)=>a.name<b.name)
/* Sort by name
[ { id: 3, name: 'charlie', job: 'doctor' },
  { id: 2, name: 'bob', job: 'engineer' },
  { id: 1, name: 'alice', job: 'engineer' } ]
*/

Chrome DevTools

Edit pages live

document.designMode='on'

• Filter network requests

status-code:200 or (NOT)-method:GET