use Data::Dumper;
use Data::Dump::Streamer;

my @ListOfRecords = qw(1 a 2 b 3 c 4 d);
my %MappingOfRecords = reverse @ListOfRecords;

print Dumper \%MappingOfRecords;
Dump \%MappingOfRecords;

##</code><code>##

$VAR1 = {
          'c' => '3',
          'a' => '1',
          'b' => '2',
          'd' => '4'
        };
$HASH1 = {
           a => 1,
           b => 2,
           c => 3,
           d => 4
         };