foreach my $sub_user_error (@db_user_errors)
{
       $worksheet->write( $row, $col, $db_error_data{$hour}{'Submission_user_error'}{$sub_user_error} or 0, $number);
       $col++;
}

##</code><code>##

#! perl
use strict;
use warnings;
use feature qw( say );

my  $hour           = 12;
my  $error          = 'Submission_user_error';
my  $sub_user_error =  3;
my  $number         = 42;
my  %db_error_data;
    $db_error_data{$hour}{$error}{$sub_user_error} =  0;

say 'With ||:';
say $db_error_data{$hour}{$error}{$sub_user_error} || 0, $number;

say 'With or:';
say $db_error_data{$hour}{$error}{$sub_user_error} or 0, $number;

##</code><code>##

22:40 >perl 1619_SoPW.pl
Useless use of private variable in void context at 1619_SoPW.pl line 17.
With ||:
042
With or:
0

22:40 >