Quick1: JS, Remove duplicates from an array

There are many ways to do this by looping over the array, then using something like .some() or .findIndex().

How about this as an elegant and simple solution?

[...new Map(users.map((item) => [item.id, item])).values()]

The use case is a collection of aggregated data that could have multiple copies of a user. I needed to remove duplicates:

const users = [
  {id: "1234", name: "kirk"},
  {id: "6789", name: "spock"},
  {id: "1234", name: "kirk"},
  {id: "1234", name: "kirk"},
  {id: "rtyu", name: "bones"},
]

console.log([...new Map(users.map((item) => [item.id, item])).values()])

Copy and paste the code below into your browser console pane to see it work

const users = [
  {id: "1234", name: "kirk"},
  {id: "6789", name: "spock"},
  {id: "1234", name: "kirk"},
  {id: "1234", name: "kirk"},
  {id: "rtyu", name: "bones"},
]

[...new Map(users.map((item) => [item.id, item])).values()]