Order an array given another array with its indices

sortFromArray.js

const A = ["d", "a", "c", "b"];
const I = [3, 0, 2, 1];

A.reduce((x, y, i, arr) => x.concat(arr[I.indexOf(i)]), []);
// > ["a", "b", "c", "d"]

// Functional Programming Power!
const sortExternalFromArray = z => (x, y, i, arr) => x.concat(arr[z.indexOf(i)]);
// A more elegant/reusable approach
A.reduce(sortExternalFromArray(I), []);
// > ["a", "b", "c", "d"] // Still working!