Access "external" Perl Array from "BEGIN" Block/Package - perl

Question

Below is a simplified version of a perl script I am trying to modify:
use MODULE_1 ;
use MODULE_2 ;
use vars qw(%ARR $VarZZ) ;
sub A {
# Somestuff
# Call to Sub B
B() ;
# Call to Sub C
C() ;
}
BEGIN {
package XYZ ;
use vars qw($VarYY $VarXX) ;
# MISC SUBS HERE
# end of package XYZ
}
sub B {
# Somestuff
}
sub C {
# Somestuff to set %ARR
}
# Call to Sub A
A() ;
My issue is that I will like to access %ARR within the package XYZ BEGIN block but keep getting error messages saying I need to define %ARR ("requires explicit package name")
I have tried, trying to copy a similar example within the block, $main::ARR{index} but failed so far.
I assume it may be because %ARR isn't set when that block is begin evaluated and that I need to call "sub C" perhaps but &main::C(); seems to be failing as well.
How can I access this array there?
I have looked at: Perl's main package - block syntax - pragmas and BEGIN/END blocks which seems to be addressing similar themes but struggling to properly understand the answers
** EDIT **
Expanded skeleton script showing some attempts at moving forward:
use MODULE_1 ;
use MODULE_2 ;
use vars qw(%ARR $VarZZ) ;
sub A {
# Somestuff
# Call to Sub B
B() ;
# Call to Sub C
C() ;
# Call to Sub E
E() ;
}
sub E {
# Call to Package XYZ subs
}
BEGIN {
package XYZ ;
use vars qw($VarYY $VarXX %ARR) ;
# I tried to Call to Sub C and load a local version of %ARR
#
# This fails with "Undefined subroutine &main::C" error
&main::C() ;
#
# We never get here so not sure if correct
%ARR = &main::ARR ;
# MISC SUBS HERE
sub X {
# Call to Sub D
&main::D() ;
}
# end of package XYZ
}
sub B {
# Somestuff
}
sub C {
# Somestuff to set %ARR
}
sub D {
# Somestuff
}
# Call to Sub A
A() ;
Note the the call to &main::E() works when called within the Subs in Package XYZ but both this and &main::C() fail when running free standing. Perhaps the free standing call is done at complile time before the subs are defined.
BTW, I tried the our definition but getting a 502 error: Nginx Debug Log
Perhaps this is because the array is not available?

Answer 1

%main:ARR or $main::ARR{index} are correct for the code skeleton you have provided (well, anything is correct because you haven't said use strict, but anyway ...). Is it possible that main is not the correct namespace (i.e., is there some pacakge statement that precedes use vars ...) ?
In any case, you can workaround this issue with the our keyword. If you declare it at the top level, it will have scope throughout the rest of the file:
package ABC;
our %ARR; # %ABC::ARR
sub foo {
$ARR{"key"} = "value"; # %ABC::ARR
}
{ # "BEGIN" optional
package XYZ;
our %Hash; # %XYZ::Hash
sub bar {
my $key1 = $Hash{"key1"}; # %XYZ::Hash
my $val1 = $ARR{$key1}; # %ABC::ARR
$ARR{$val1} = $key1;
}
}
...