Handles any nesting of [] and {}

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11111985
use warnings;
use List::Util qw( sum0 );

my $orders = [
    {
        'OrderDate'      => '2019-11-01 00:00:00',
        'AlternateKey'   => 'D',
        'Customer'       => '1238756',
        'SalesOrder'     => '10928',
        'CustomerName'   => 'Dunder Mifflin',
        'ShippingInstrs' => 'Standard'
    },
    {
        'OrderDate'      => '2020-01-15 00:00:00',
        'SalesOrder'     => '11349',
        'Customer'       => '1239451',
        'AlternateKey'   => 'R',
        'CustomerName'   => 'Vance Refrigeration',
        'ShippingInstrs' => 'Standard'
    },
    {
        'OrderDate'      => '2020-01-22 00:00:00',
        'SalesOrder'     => '12954',
        'Customer'       => '1240029',
        'AlternateKey'   => 'R',
        'CustomerName'   => 'A1A Car Wash',
        'ShippingInstrs' => 'Next Day'
    }
];

sub charcount
  {
  my $tree = shift;
  ref $tree or return length $tree;
  sum0 map charcount($_), ref $tree eq 'HASH' ? %$tree : @$tree;
  }

print charcount($orders), "\n";
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