Ungroup array elements based on function

OSCC · JavaScript, Array · Jan 23, 2022

Creates an array of elements, ungrouping the elements in an array produced by zip and applying the provided function.

const unzipWith = (arr, fn) =>
  arr
    .reduce(
      (acc, val) => (val.forEach((v, i) => acc[i].push(v)), acc),
      Array.from({
        length: Math.max(...arr.map(x => x.length))
      }).map(x => [])
    )
    .map(val => fn(...val));
unzipWith(
  [
    [1, 10, 100],
    [2, 20, 200],
  ],
  (...args) => args.reduce((acc, v) => acc + v, 0)
);
// [3, 30, 300]

Recommended snippets

  • Ungroup array elements

    JavaScript, Array

    Creates an array of arrays, ungrouping the elements in an array produced by zip.

  • Returns the elements that exist in both arrays, after applying the provided function to each array element of both.

  • Creates an array of elements, grouped based on the position in the original arrays and using a function to specify how grouped values should be combined.