Re^2: Replacing values in an array

[eyepopslikeamosquito]

Using for instead of map:

use strict;
use warnings;
use Data::Dumper;
my @a = ("M94202", "M94150", "M94297", "M94150", "M94161", "M94161", "
+M94162");
my ( $n,  %h ) = -1;
$_ = $h{$_} //= $n+=2 for @a;
print Dumper \@a;

I suppose if you were playing golf, without use strict, you might write:

my ( $n,  %h ) = -1;
$_ = $h{$_} //= $n+=2 for @a;

in one-line as:

$_=$h{$_}//=$}+=2-!$}for@a;

(/me ducks)