Ungroup array elements based on function
JavaScript, Array · Jan 23, 2022
Creates an array of elements, ungrouping the elements in an array produced by zip and applying the provided function.
- Use
Math.max()and the spread operator (...) to get the longest subarray in the array,Array.prototype.map()to make each element an array. - Use
Array.prototype.reduce()andArray.prototype.forEach()to map grouped values to individual arrays. - Use
Array.prototype.map()and the spread operator (...) to applyfnto each individual group of elements.
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]
