js_intersection_union.js

// -------------------   intersection of two arrays   ------------------- //
let setA = new Set([1, 2, 3, 4, 8]);
let setB = new Set([4, 3, 2, 10, 7]);
let tmpIntersection = new Set([...setA].filter(x => setB.has(x)));
console.log(tmpIntersection);  
// return   Set { 2, 3, 4 }

console.log( [...setA].filter(x => setB.has(x)) )
// return   [ 2, 3, 4 ]

// -------------------   setA - setB   ------------------- //
let setAMinusSetB = new Set([...setA].filter(x => !setB.has(x)));
console.log(setAMinusSetB)
// return    Set { 1, 8 }

// -------------------   union of two arrays   ------------------- //
var union = [...new Set([...setA, ...setB])];
console.log(union)
// return .  [ 1, 2, 3, 4, 8, 10, 7 ]