From: Jamis Buck <jgb3@...>
Date: 2003-12-18T04:30:22+09:00
Subject: Re: gsub question

Daniel Bretoi wrote:

>perl -e '$a="hello hi hello";$a =~ s/(\w+)/$1a/g;print $a; '
>helloa hia helloa
>
>ruby -e 'a="hello hi hello";a.gsub!(/(\w+)/,"#{$1}a"); puts a'
>a a a
>
>Why?  I'm expecting the same result as in perl.
>  
>

Because the $1 isn't defined at the time the replacement string is 
parsed.  Instead, use \1:

  ruby -e 'a="hello hi hello";a.gsub!(/(\w+)/, '\1a');puts a'
  hello hia helloa

-- 
Jamis Buck
jgb3@email.byu.edu

ruby -h | ruby -e 'a=[];readlines.join.scan(/-(.)\[e|Kk(\S*)|le.l(..)e|#!(\S*)/) {|r| a << r.compact.first };puts "\n>#{a.join(%q/ /)}<\n\n"'