Your code should read:

%person = (
             firstname => ['name1', 'name2', 'name3'],
             lastname => ['lname1', 'lname2', 'lname3'],
             city => ['city1','city2','city3']
          );
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or

$person = {
             firstname => ['name1', 'name2', 'name3'],
             lastname => ['lname1', 'lname2', 'lname3'],
             city => ['city1','city2','city3']
          };
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If you really need your data to look like this you can sort it like this.

%person = (
             firstname => ['name2', 'name1', 'name3'],
             lastname => ['lname2', 'lname1', 'lname3'],
             city => ['city2','city1','city3']
          );

for (map {$_->[1] }
      sort {$a->[0] cmp $b->[0] }
       map { [$person{firstname}[$_], $_] }
        (0 .. scalar @{$person{firstname}} - 1)) {
    printf("%s %s %s\n",
           $person{firstname}[$_],
           $person{lastname}[$_],
           $person{city}[$_]);
}
[download]