Mixed hash not working correctly - perl

Question

I'm creating this hash
my %obj_cuentascontables = {
'4210' => {
'banderamayor' => 'true',
'enlace' => 'true',
'not_rlike_nombre' => 'DEVOLUCION'
},
'4410' => {
'banderamayor' => 'true',
'enlace' => 'true',
'rlike_nombre' => 'DEVOLUCION',
'categoria_cuenta' => 'DEVOLUCIONES REBAJAS Y DESCUENTOS'
}
};
my %param = {
'concepto_ID' => "$concepto_ID",
'formato_ID' => $formato_ID,
'obj_cuentascontables'=> { %obj_cuentascontables },
};
And later I Dump %param and i get this:
$VAR1 = {
'concepto_ID' => '5501',
'formato_ID' => 1001,
'obj_cuentascontables' => {
'HASH(0xf16eb70)' => undef
}
};
I can't use that 'HASH' Thing, so, i was trying to see if i was referencing incorrectly the hash and i create another one very similar.
my %obj_cuentascontables = ();
$obj_cuentascontables{'4210'}{'banderamayor'} = 'true';
$obj_cuentascontables{'4210'}{'enlace'} = 'true';
$obj_cuentascontables{'4210'}{'not_rlike_nombre'} = 'DEVOLUCION';
$obj_cuentascontables{'4410'}{'banderamayor'} = 'true';
$obj_cuentascontables{'4410'}{'enlace'} = 'true';
$obj_cuentascontables{'4410'}{'rlike_nombre'} = 'DEVOLUCION';
$obj_cuentascontables{'4410'}{'categoria_cuenta'} = 'DEVOLUCIONES REBAJAS Y DESCUENTOS';
my %param = ();
$param{'concepto_ID'}= $concepto_ID;
$param{'formato_ID'} = $formato_ID;
$param{'obj_cuentascontables'} = \%obj_cuentascontables;
And then Dumper return this:
$VAR1 = {
'concepto_ID' => 5501,
'formato_ID' => 1001,
'obj_cuentascontables' => {
'4410' => {
'enlace' => 'true',
'rlike_nombre' => 'DEVOLUCION',
'categoria_cuenta' => 'DEVOLUCIONES REBAJAS Y DESCUENTOS',
'banderamayor' => 'true'
},
'4210' => {
'enlace' => 'true',
'not_rlike_nombre' => 'DEVOLUCION',
'banderamayor' => 'true'
}
}
};
My question is, WHY?!!!... I want the second Dump in my first structure... It is possible?

Answer 1

If you look carefully at how you constructed the hash in the first snippet, you used curly braces {}. In the context of your assignment, this is assigning a hash reference to your hash.
What you need are round brackets ():
my %obj_cuentascontables = (
'4210' => {
'banderamayor' => 'true',
'enlace' => 'true',
'not_rlike_nombre' => 'DEVOLUCION'
},
'4410' => {
'banderamayor' => 'true',
'enlace' => 'true',
'rlike_nombre' => 'DEVOLUCION',
'categoria_cuenta' => 'DEVOLUCIONES REBAJAS Y DESCUENTOS'
}
);
This is why you should use warnings;, as it would warn you about this:
Reference found where even-sized list expected ...

Answer 2

Always use use strict; use warnings;! The latter would have identified the error.
$ perl -e'use strict; use warnings; my %obj_cuentascontables = { };'
Reference found where even-sized list expected at -e line 1.
You are assigning a hash reference to a list when it expects a list of scalars to use as keys and values. Keep in mind that
{ ... }
is roughly
do { my %anon = ( ... ); \%anon }
so
my %obj_cuentascontables = { ... };
should be
my %obj_cuentascontables = ( ... );

Answer 3

You're not using use warnings; which would have helped you see the odd-number error.
I assume you want your $param{obj_cuentascontables} to point to the hash %obj_cuentascontables. That way, you can refer to:
$param{obj_cuentascontables}->{4210}->{banderamayor}
as having the value of true.
You need to assign a reference to your %obj_cuentascontables hash for the value of the obj_cuentascontables key in your %param hash.
my %param = {
concepto_ID => "$concepto_ID",
formato_ID => $formato_ID,
obj_cuentascontables => \%obj_cuentascontables,
};
My preference is to use the -> syntax when referring to references. Officially, these are both the same:
$param{obj_cuentascontables}->{4210}->{banderamayor}
$param{obj_cuentascontables}{4210}{banderamayor}
However, I find that using the -> syntax reminds me this is not really a hash, but a reference to a hash. This helps me get the syntax right when I build these complex data structures.
What you did was similar to this:
my $hash_address = sprintf "%s", \%obj_cuentascontables; # Stingifying the hash reference
$param{obj_cuentascontables} = { };
$param{obj_cuentascontables} = { $hash_address => }; # Not 100% Perl will parse this...
You assigned a hash reference to $param{obj_cuentascontables} which is what you want, but you then used the address of the hash as the key, and no value.