Some giraffes like to be touched while other giraffes may not like to be touched.
The giraffes in the wild may not like to be touched but then again some wild giraffes may like to be touched and petted.
I have petted a few giraffes in the wild and they loved it and they actually reached down with their head and rubbed it against my head to show me love just like I showed it love.
If you do want to pet a giraffe or touch one the best thing to do is go to a zoo and they will be more likely to let you touch the giraffe.
Giraffes in zoos are more used to humans and may enjoy the human touching it and petting it.