Hashes

use strict;
use warnings;
use feature 'say';

my %units = (Nairobi => 12, Mombasa => 8);
say $units{Nairobi};

use strict;
use warnings;
use feature 'say';

my %row = (city => "Kisumu", units => 5);
say $row{city};
say $row{units};

use strict;
use warnings;
use feature 'say';

my %kiosks = (Nairobi => 12, Kisumu => 5);
$kiosks{Eldoret} = 3;
say join(",", keys %kiosks);

use strict;
use warnings;
use feature 'say';

my %units = (Nairobi => 12, Nakuru => 4);
my $sum = 0;
$sum += $_ for values %units;
say $sum;