Ruby gsub doesn't escape single-quotes

问题

I don't understand what is going on here. How should I feed gsub to get the string "Yaho\'o"?

>> "Yaho'o".gsub("Y", "\\Y")
=> "\\Yaho'o"
>> "Yaho'o".gsub("'", "\\'")
=> "Yahooo"

回答1:

\' means $' which is everything after the match. Escape the \ again and it works

"Yaho'o".gsub("'", "\\\\'")

回答2:

"Yaho'o".gsub("'", "\\\\'")

Because you're escaping the escape character as well as escaping the single quote.

回答3:

This will also do it, and it's a bit more readable:

def escape_single_quotes(str)
  str.gsub(/'/) { |x| "\\#{x}" }
end

If you want to escape both a single-quote and a backslash, so that you can embed that string in a double-quoted ruby string, then the following will do that for you:

def escape_single_quotes_and_backslash(str)
  str.gsub(/\\|'/) { |x| "\\#{x}" }
end

来源：https://stackoverflow.com/questions/2180322/ruby-gsub-doesnt-escape-single-quotes