30-seconds-of-code/snippets/js/s/superset.md

title, type, language, tags, cover, dateModified

title	type	language	tags	cover	dateModified
Superset of iterable	snippet	javascript	array	waves-from-above-2	2020-10-22T20:24:30+03:00

Checks if the first iterable is a superset of the second one, excluding duplicate values.

• Use the Set constructor to create a new Set object from each iterable.
• Use Array.prototype.every() and Set.prototype.has() to check that each value in the second iterable is contained in the first one.

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

superSet(new Set([1, 2, 3, 4]), new Set([1, 2])); // true
superSet(new Set([1, 2, 3, 4]), new Set([1, 5])); // false