Re: Different Type of Hashes

[Khen1950fx]

#2 is the correct way to initialize the hash with an even-sized list. #1 and #3---the brackets are in effect creating a reference which isn't what you want.

[johngg]

Neither, I think, is #2!

knoppix@Microknoppix:~$ perl -Mstrict -MData::Dumper -wE '
> my %h = (
>    ( 1 => q{j}, 2 => q{b} ),
>    ( 1 => q{p}, 2 => q{b} ),
>    );
> print Data::Dumper->Dumpxs( [ \ %h ], [ qw{ *h } ] );'
%h = (
       '1' => 'p',
       '2' => 'b'
     );
knoppix@Microknoppix:~$

It is not clear from the three attempts what the OP desires. If a HoH is the aim then there should be a key with a value of the inner hash reference.

knoppix@Microknoppix:~$ perl -Mstrict -MData::Dumper -wE '
> my %h = (
>    k1 => { 1 => q{j}, 2 => q{b} },
>    k2 => { 1 => q{p}, 2 => q{b} },
>    );
> print Data::Dumper->Dumpxs( [ \ %h ], [ qw{ *h } ] );'
%h = (
       'k2' => {
                 '1' => 'p',
                 '2' => 'b'
               },
       'k1' => {
                 '1' => 'j',
                 '2' => 'b'
               }
     );
knoppix@Microknoppix:~$

An AoH fits the OP's data best perhaps?

knoppix@Microknoppix:~$ perl -Mstrict -MData::Dumper -wE '
> my @a = (
>    { 1 => q{j}, 2 => q{b} },
>    { 1 => q{p}, 2 => q{b} },
>    );
> print Data::Dumper->Dumpxs( [ \ @a ], [ qw{ *a } ] );'
@a = (
       {
         '1' => 'j',
         '2' => 'b'
       },
       {
         '1' => 'p',
         '2' => 'b'
       }
     );
knoppix@Microknoppix:~$

It would be useful if the OP could clarify their requirement.