$ perl -Mstrict -Mwarnings -MData::Dumper -e ' > my $oddNos = do { > my $val = -1; > sub { $val += 2; }; > }; > > my @array = qw{ > M94202 > M94150 > M94297 > M94150 > M94161 > M94161 > M94162 > }; > > @array = do { > my %seen; > map { > exists $seen{ $_ } > ? $seen{ $_ } > : do { > $seen{ $_ } = $oddNos->(); > $seen{ $_ }; > }; > } @array; > }; > > print Data::Dumper->Dumpxs( [ \ @array ], [ qw{ *array } ] );' @array = ( 1, 3, 5, 3, 7, 7, 9 ); $