$ npm i lodash
import _ from 'lodash
_.uniq([1,1,2])
배열 원소 중복 제거 -> [1,2] 반환const usersC = userA.concat(usersB)
+ console.log(_.uniqBy(usersC, 'userId'))
console.log(_.unionBy(userA, userB, 'userId'))
const foundUser = _.find(users, { name: 'Loopy' })
const foundUserIndex = _.findIndex(users, { name: 'Loopy' })
_.remove(users, { name: 'Loopy' })