JS: Set.prototype.intersection

By Xah Lee. Date: . Last updated: .

(new in JS: ECMAScript 2024)

setA.intersection(setB)
  • return the intersection of 2 sets.
  • setB can be a Map.
const xx = new Set([4, 5, 6])
const yy = new Set([6, 7, 8])
console.log(xx.intersection(yy))
// Set(1) { 6 }

// intersection of 2 map's keys

const mapA = new Map([[4, 0], [5, 0], [6, 0]])
const mapB = new Map([[6, 0], [7, 0], [8, 0]])

console.log((new Set(mapA.keys())).intersection(mapB))
// Set(1) { 6 }

JS set operations