zip

JavaScript, Array

Creates an array of elements, grouped based on their position in the original arrays.

  • Use Math.max(), Function.prototype.apply() to get the longest array in the arguments.
  • Create an array with that length as return value and use Array.from() with a mapping 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(...arrays.map(x => x.length));
  return Array.from({ length: maxLength }).map((_, i) => {
    return Array.from({ length: arrays.length }, (_, k) => arrays[k][i]);
  });
};
Examples
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]]

Recommended snippets

  • zipWith

    JavaScript, Array

    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.

  • unzipWith

    JavaScript, Array

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

  • unzip

    JavaScript, Array

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