When I first learned Perl I used to be annoyed that $x =~ s/.../.../ changed $x. Often I wanted both the original value and the transformed around. I thought I had no choice but this two liner. To my eyes, this is just plain confusing since $transformed isn't transformed (yet):

  my $transformed=$original;
  $transformed =~ s/.../.../;
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Then I discovered that I could keep the original and the transformed value by doing this one liner:

(my $transformed=$original) =~ s/.../.../;
[download]

Best, beth