#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;

my %hash = (
   a => [ '1','2', ],
   b => [ '2','3', ],
   c => [ '1','2', ],
);


print Dumper \%hash;

print "Delete whole key containing aref\n\n";
delete $hash{a};
print Dumper \%hash;

print "Will turn to undef, perldoc -f delete says dont do it\n\n";
delete $hash{b}->[0];
print Dumper \%hash;

print "Delete an element\n\n";
splice @{$hash{c}},0,1;
print Dumper \%hash;


# Returns
$VAR1 = {
          'c' => [
                   '1',
                   '2'
                 ],
          'a' => [
                   '1',
                   '2'
                 ],
          'b' => [
                   '2',
                   '3'
                 ]
        };
Delete whole key containing aref

$VAR1 = {
          'c' => [
                   '1',
                   '2'
                 ],
          'b' => [
                   '2',
                   '3'
                 ]
        };
Will turn to undef, perldoc -f delete says dont do it

$VAR1 = {
          'c' => [
                   '1',
                   '2'
                 ],
          'b' => [
                   undef,
                   '3'
                 ]
        };
Delete an element

$VAR1 = {
          'c' => [
                   '2'
                 ],
          'b' => [
                   undef,
                   '3'
                 ]
        };