Search and replace in vim in specific lines

Question

I can use

:5,12s/foo/bar/g

to search for foo and replace it by bar between lines 5 and 12. How can I do that only

Answer 1

You can do the substitution on line 5 and repeat it with minimal effort on line 12:

:5s/foo/bar
:12&

As pointed out by Ingo, :& forgets your flags. Since you are using /g, the correct command would be :&&:

:5s/foo/bar/g
:12&&

See :help :& and friends.