How to duplicate a file/class inside File Inspector of Xcode?
I've tried using CMD+C then CMD+V but it did not worked?
It's really annoying I know that this does not work. However, as a workaround, try finding the file in finder and right-clicking / two-finger-clicking it there and selecting Duplicate.
UPDATE: I have found that if you use the keyboard shortcut Command + Shift + S while selecting the file it will duplicate (go to file -> Duplicate)
Dragging file to a desired position in file inspector while holding option/alt
key will duplicate the file.
If you drag file inside the same folder in the file inspector it will add a copy
suffix to its name to prevent file name collission otherwise just copy it to new place.