Ruby regex - gsub only captured group

Question

I\'m not quite sure I understand how non-capturing groups work. I am looking for a regex to produce this result: 5.214. I thought the regex below would work, bu

Answer 1

It is also possible to use Regexp.last_match (also available via $~) in the block version to get access to the full MatchData:

"5,214".gsub(/(\d),(\d)/) { |_|
    match = Regexp.last_match

    "#{match[1]}.#{match[2]}"
}

This scales better to more involved use-cases.

Nota bene, from the Ruby docs:

the ::last_match is local to the thread and method scope of the method that did the pattern match.