How to do substitution in the selected part of a line instead of the whole line? [duplicate]

Question

I want to do substitution in a partial of a line.
But when I type :'<,'>s/xx/yy/g, it always do it in the whole line.
How can I tell vim to do it in the exact selection area??

Answer 1

Add \%V to your search. From :h /\%V:

                        */\%V*
\%V Match inside the Visual area.  When Visual mode has already been
    stopped match in the area that |gv| would reselect.
    This is a |/zero-width| match.  To make sure the whole pattern is
    inside the Visual area put it at the start and end of the pattern,
    e.g.: >
        /\%Vfoo.*bar\%V
<   Only works for the current buffer.

So you want to do :'<,'>s/\%Vxx/yy/g