symmetricDifferenceintermediateconst a = new Set([1, 2, 3])
const b = new Set([2, 3, 4])
const sym = a.symmetricDifference(b)
console.log([...sym]) // β [1, 4]Use Set.symmetricDifference() to get elements in either set but not in both.
symmetricDifference() does not modify the original Sets.
Challenge: Verify originals are unchanged.