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Flatten Nested Array
basicjavascript
Background
Array flattening is essential when processing tree-like data structures or normalizing API responses with nested arrays.
Problem
Write a function that takes an array which may contain nested arrays of arbitrary depth and returns a fully flattened array.
Input
An array that may contain numbers, strings, or nested arrays at any depth.
Output
A flat array with all nested elements extracted to a single level.
Sample tests
Sample 1
Input: [1, [2, [3, [4]]]]
Expected: [1, 2, 3, 4]
Your solution
Learning objective
Learn recursive array processing and understand depth handling in flattening.