isDisjoint

Checks if the two iterables are disjointed (have no common values).

• Use the new Set() constructor to create a new Set object from each iterable.
• Use Array.prototype.every() and Set.prototype.has() to check that the two iterables have no common values.

const isDisjoint = (a, b) => {
  const sA = new Set(a), sB = new Set(b);
  return [...sA].every(v => !sB.has(v));
};

isDisjoint(new Set([1, 2]), new Set([3, 4])); // true
isDisjoint(new Set([1, 2]), new Set([1, 3])); // false