w3resource

JavaScript: Ungrouping the elements in an array produced by zip

JavaScript Array: Exercise-43 with Solution

Write a JavaScript function to create an array of arrays, ungrouping the elements in an array produced by zip.

Use Math.max(), Function.prototype.apply() to get the longest subarray in the array, Array.prototype.map() to make each element an array.
Use Array.prototype.reduce() and Array.prototype.forEach() to map grouped values to individual arrays.

Sample Solution:

JavaScript Code :

// Source: https://bit.ly/3hEZdCl
// Function to unzip an array of arrays
const unzip = arr =>
  // Reduce the array, merging elements by index
  arr.reduce(
    (acc, val) => (val.forEach((v, i) => acc[i].push(v)), acc),
    // Initialize an array with empty arrays, one for each index
    Array.from({
      length: Math.max(...arr.map(x => x.length))
    }).map(x => [])
  );

// Output the result of unzipping the given arrays
console.log(unzip([['a', 1, true], ['b', 2, false]]));
console.log(unzip([['a', 1, true], ['b', 2]]));

Output:

[["a","b"],[1,2],[true,false]]
[["a","b"],[1,2],[true]]

Flowchart :

JavaScript array flowchart: Ungrouping the elements in an array produced by zip.

Live Demo :

See the Pen javascript-common-editor by w3resource (@w3resource) on CodePen.


Improve this sample solution and post your code through Disqus.

Previous: Write a JavaScript function to find the unique elements from two arrays.
Next: Write a JavaScript function to create an object from an array, using the specified key and excluding it from each value.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://www.w3resource.com/javascript-exercises/javascript-array-exercise-43.php