Sets in JavaScript are quite useful as they are like an array, but can only contain one of a specific item. So you can unique-ify an array easily, and even willy-nilly add stuff to it and not worry about duplicates:
const people = ["chris", "chris", "cindy"];
const peopleSet = new Set(people);
peopleSet.add("chris");
console.log(peopleSet);
// {"chris","cindy"}Code language: JavaScript (javascript)Now they are even more useful with recently universally available methods, as Brian Smith summarizes:
intersection()returns a new set with elements in both this set and the given set.union()returns a new set with all elements in this set and the given set.difference()returns a new set with elements in this set but not in the given set.symmetricDifference()returns a new set with elements in either set, but not in both.isSubsetOf()returns a boolean indicating if all elements of a set are in a specific set.isSupersetOf()returns a boolean indicating if all elements of a set are in a specific set.isDisjointFrom()returns a boolean indicating if this set has no elements in common with a specific set.