How to Convert an Array into a Complex Array JavaScript ?

Complex arrays can represent multiple dimensions or data with a structure. This article discusses two approaches to converting an array into a more complex array.

Using Multidimensional Arrays

The simplest approach is to create inner arrays within the main array. You can achieve this using array literals and assignments.

Example: Creating a multidimensional array from a simple array with subarrays of two elements each.

JavaScript

const simpleArray = [1, 2, 3, 4, 5, 6];
const multidimensionalArray = [
  [simpleArray[0], simpleArray[1]],  // First subarray
  [simpleArray[2], simpleArray[3]],  // Second subarray
  [simpleArray[4], simpleArray[5]]   // Third subarray 

console.log(multidimensionalArray); 

Output:

[ [ 1, 2 ], [ 3, 4 ], [ 5, 6 ] ]

Time Complexity: O(n)

Space Complexity: O(n)

Using Array.from()

This approach provides a versatile approach to building multidimensional arrays. It can be used in combination with a mapping function to change the initial array.

Example: Creating a multidimensional array from a simple array by splitting into subarrays of two elements each using `Array.from()` and indices.

JavaScript

const simpleArray = [1, 2, 3, 4, 5, 6];

const multidimensionalArray = 
Array.from({ length: Math.ceil(simpleArray.length / 2) }, (_, i)
   => [
  simpleArray[i * 2],
  simpleArray[i * 2 + 1] || null 
]);

console.log(multidimensionalArray); 

Output

[ [ 1, 2 ], [ 3, 4 ], [ 5, 6 ] ]

Time Complexity: O(n)

Space Complexity: O(n)