what does it mean to log the input to the console. Can you explain please?

using console.log

you can log the input to the console to see what you're missing on

If the input array is empty or null, return an empty array.

null is not an array, so that's already there. Maybe it could be worded in some other way.

Changed to this:

If the input is an empty array or is null, return an empty array.