use warnings;
use strict;

my @AoH = (
    {
       a  => "a1",
       b  => "b1",
       c   => "c1",
    },
    {
       d => "d1",
       e    => "e1",
       f     => "f1",
    },

    {
       g => "g1",
       h    => "h1",
       i     => "i1",
    },
  );

for my $i (0 .. $#AoH) {
    for my $key (keys %{ $AoH[$i] }) {
        print "$i $key\n";
    }
}