c:\@Work\Perl\monks>perl -wMstrict -le
"for (qw(a X b)) {
   /(a)/ or /(b)/;
   my $id = $1;
   print qq{'$_' -> '$id'};
   }
"
'a' -> 'a'
'X' -> 'a'
'b' -> 'b'

##</code><code>##

c:\@Work\Perl\monks>perl -wMstrict -le
"for (qw(a X b)) {
   /(a)|(b)/ or next;
   my $id = $1 // $2;
   print qq{'$_' -> '$id'};
   }
"
'a' -> 'a'
'b' -> 'b'