Reference groups in search and replace in Vim
A group is defined with parentheses and they must be backspaced:
\(group_regex\). You can reference groups from the “search” regex into the “replace” regex with
x is the number of the group.
Let’s say you want to add dashes around digits in a text file, from “today is 20 May 2022” to “today is -2–0- May -2–0–2–2-”. You can do it like this: