30-seconds-of-code/snippets/array-zip.md

Array zip

Use Math.max.apply to get the longest array in the arguments. Creates an array with that length as return value and use Array.from with a map-function to create an array of grouped elements. If lengths of the argument-arrays vary, undefined is used where no value could be found.

const zip = (...arrays) => {
  const maxLength = Math.max.apply(null, arrays.map(a => a.length));
  return Array.from({length: maxLength}).map((_, i) => {
   return Array.from({length: arrays.length}, (_, k) => arrays[k][i])
  })
}

//zip(['a', 'b'], [1, 2], [true, false]); -> [['a', 1, true], ['b', 2, false]]
//zip(['a'], [1, 2], [true, false]); -> [['a', 1, true], [undefined, 2, false]]