shortened forms

Hello,
I think sentence 1 is okay, but I am not sure 2/ is right. Would you please help me with that? Thanks a lot.
1/ She has some friends, but he doesn't have any.
2/ She has some friends, but he doesn't.
What is that sort of shortened sentences called? Ellipsis forms?
Thanks a lot for helping me. Have a nice day. 👁 Smile :)

I don't know what they are called, but they are both correct.

Thanks a lot for helping me. 👁 Smile :)

As for a name, this ellipsis might be the kind called stripping. This is where the second part is reduced to a single element, marked with some kind of focus like 'also'/'too' or 'not':

She invited many of her friends, but not Tom.
She invited all her girlfriends, and Tom too.

In your example, we have a focused element 'he', and the verb 'doesn't' is really just a negative. Although it's technically subject + verb, it has the same effect as 'but not him/Tom'.

Thanks a lot 👁 Smile :)