JavaScript Check if Key Exists in Deeply Nested Object or Array of Objects, Without Knowing the Path

Depth First Search (DFS) for Key Verification in an Object

The following JavaScript code recursively goes through the whole object, an array of objects, or a collection of both to verify if the given key exists somewhere down the object. It does not require the path to the key in advance.

A similar recursive solution as below can also be used to modify all the keys of a deeply nested object or array of objects.

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