Flatten with Depth

Challenge summary

Flatten nested arrays only to a requested depth while preserving item order and the source array.

What you'll practice

• Interpret zero, finite, and excessive depth values consistently.
• Preserve the left-to-right order of every retained item.
• Return a new array without mutating nested input arrays.

What Premium unlocks

Premium unlocks the runnable workspace, behavioral checks, implementation walkthrough, and edge-case discussion.