JSFiddle - React, Tailwind, and code Playground

JavaScript

var mySet = new Set();
var mySet2=new Set();
mySet.add(1);
mySet.add(2);
mySet.add("HELLOOOOO");
mySet2.add("hi");
mySet2.add(1);

console.log(intersection_destructive(mySet, mySet2));

function intersection_destructive(a, b)
{
    
    // filter over the shorter set and convert sets to Array's so we have filter
    if (a.length > b.length) {
        var array1 = Array.from(a);
        var array2 = Array.from(b);
    } else {
        var array1 = Array.from(b);
        var array2 = Array.from(a);
    }
    
    var result = array1.filter(function(n) {
        return array2.indexOf(n) != -1
    });
    
    return result;
}