Finding intersection in multiple arrays

Question

I am trying to find the intersecting values in multiple arrays, that are within an object as follows:

object = {
  filterA: ["1","2","3","4"],
  filterB: ["2","5","6","7"],
  filterN: ["2","4","7"]
}

The object can hold multiple arrays and the name of the keys can vary. In the described object I need only "2" to be returned.

I have tried to build on this answer: Multiple array intersection in javascript but I could not figure it out, as it uses static variables (a,b,c) for the example. If there is a way to do that with lodash, it will be appreciated, but vanilla javascript in ES 5 will do as well!

Answer 1

You could get the values and take a Set and filter with Set#has.

var object = { filterA: ["1", "2", "3", "4"], filterB: ["2", "5", "6", "7"], filterN: ["2", "4", "7"] },
    result = Object
        .values(object)
        .reduce((a, b) => b.filter(Set.prototype.has, new Set(a)));

console.log(result);