Unzip an array of arrays

Regroup the n-th item of every array into the n-th output array.

JavaScript Version 1.0.0 · MIT · .md

function unzip(arrays) { return Array.from({ length: Math.max(0, ...arrays.map(array => array.length)) }, (_, i) => arrays.filter(array => i < array.length).map(array => array[i])); }

Input & expected output

[
  [
    "[email protected]",
    "delivered"
  ],
  [
    "[email protected]",
    "deferred"
  ]
]

[
  [
    "[email protected]",
    "[email protected]"
  ],
  [
    "delivered",
    "deferred"
  ]
]

The edge case

[]

[]

Know the limits

• Shorter arrays simply contribute fewer items.
• The inverse of Zip multiple arrays.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Clone an array — Create a new array without copying the objects inside it.
• Remove duplicate values — Keep the first occurrence of each value, in its original order.
• Flatten a nested array — Turn a nested array into one sequence of values.