Or perhaps more clearly: 
my $me = "old me";
s1($me);
print "$me\n";

sub s1 {
  $_[0] = "new me";
}

[download]
But it's customary to make local copies of the parameters like 'my $var = shift' so they don't get changed.

In reply to Re^2: Text::ExtractWords exhibits incomprehensible behavior? by Danny
in thread Text::ExtractWords exhibits incomprehensible behavior? by ibm1620

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