How to backreference in Ruby regular [removed]regex) with gsub when I use grouping?

Question

I would like to patch some text data extracted from web pages. sample:

t=\"First sentence. Second sentence.Third sentence.\"

There is no sp

Answer 1

You can backreference in the substitution string with \1 (to match capture group 1).

t = "First sentence. Second sentence.Third sentence!Fourth sentence?Fifth sentence."
t.gsub(/([.!?])([A-Z1-9])/, "\\1\n\\2") # => "First sentence. Second sentence.\nThird sentence!\nFourth sentence?\nFifth sentence."