.padStart()

padStart get 'Turtle' with 10 spaces in front of it

.padEnd()

padEnd get 'Turtle' with 10 spaces after it

trailing commas(후행쉼표)

const fun = (
	a,
	b,
	c,
	d,) => {
    console.log(a);
}

fun(1,2,3,4,)

Everytime you add a new parameter, it's a lot easier.

Object.values

Object.entries

'Object.keys' allowed us to do something similar to arrays but on objects.

Object.keys

let obj = {
	username0: 'Santa',
	username1: 'Rudolph',
	username2: 'Mr.Grinch'
}

Object.keys(obj).forEach((key, index) => {
	console.log(key, obj[key]);
})

Object.values

Object.values(obj).forEach(value => {
	console.log(value);
})

Object.entries

Object.entries(obj).forEach(value => {
	console.log(value);
})

Example.

let obj = {
	username0: 'Santa',
	username1: 'Rudolph',
	username2: 'Mr.Grinch'
}

1. We receive this data values from the backend.
2. The backend just send us a bunch of users that they had in the database
3. We want to generate 'usernames' for that. (We don't want username0, username1, username2)

Object.entries(obj).map(value => {
	return value[1] + value[0].replace('username', '');
})