Why the quote is placed at the beginning of string?

Question

To match the string behind the : :

TE: trailer

The expression will convert the string into trailer:

:1s/\v(.{-}):\s{1,}(.{-})/\2/

Why 1s/\v(.{-}):\s{1,}(.{-})/\2""/ convert the string into ""trailer instead of trailer""?

Almost the same result:1s/\v(.{-}):\s{1,}(.{-})/"\2"/ convert the string into ""trailer instead of "trailer"

Answer 1

Second capture group is non-gready and it captures nothing, so you essentially replace only TE: with \2 which is empty and "", and the result is ""trailer.

1s/\v(.{-}):\s{1,}(.*)/\2""/

or

1s/\v(.{-}):\s{1,}(.{-})$/\2""/

would make it trailer""

and

1s/\v(.{-}):\s{1,}(.{-})$/\2""/

to make it "trailer".