Returns the array associated with the specified key.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
A key in the current user‘s defaults database.
The array associated with the specified key, or
nil if the key does not exist or its value is not an array.
The returned array and its contents are immutable, even if the values you originally set were mutable.