Array flat in javascript

Medium

How can you implement a function to flatten a nested array of arbitrary depth?

ArraysFlatRecursionJavascript

1const nestedArray = [1, [2, [3, [4]]]];
2const flattenArray = (arr) => {
3  // Your implementation here
4};
5
6console.log(flattenArray(nestedArray)); // Expected: [1, 2, 3, 4]

How can you implement a function to flatten a nested array of arbitrary depth?

Hint