Get the cartesian product of multiple sets

cartesianProduct.js

// Thanks to eddmann.com/posts/cartesian-product-in-javascript

const cartesianProduct = (...sets) =>
  sets.reduce((sets, set) => sets.flatMap(x => set.map(y => [...x, y])), [[]]);

cartesianProduct(
  ['a', 'b', 'c'],
  ['x', 'y', 'z'],
);

// [
//   ["a", "x"],
//   ["a", "y"],
//   ["a", "z"],
//   ["b", "x"],
//   ["b", "y"],
//   ["b", "z"],
//   ["c", "x"],
//   ["c", "y"],
//   ["c", "z"],
// ]