30-seconds-of-code/snippets/intersectionWith.md

intersectionWith

Returns a list of elements that exist in both arrays, using a provided comparator function.

Use Array.filter() and Array.findIndex() in combination with the provided comparator to determine intersecting values.

const intersectionWith = (a, b, comp) =>
  a.filter(x => b.findIndex(y => comp(x, y)) !== -1);

intersectionWith([1, 1.2, 1.5, 3, 0], [1.9, 3, 0, 3.9], (a, b) => Math.round(a) === Math.round(b)); // [1.5, 3, 0]