#!/usr/bin/perl

# https://perlmonks.org/?node_id=1232659

use strict;
use warnings;
use List::Util qw( reduce );

my %hashName = (a => 1, b => 3, c => 3);

sub allmax
  {
  reduce { $a->[-1] > $b->[-1] ? $a :
    $a->[-1] < $b->[-1] ? $b :
    [ @{$a}[0..@$a-2], @$b ] } @_;
  }

my $maxref = allmax( map [ $_, $hashName{$_} ], sort keys %hashName );

print "@$maxref\n";
[download]

Outputs:

b c 3
[download]

[-@$a..-2] would have been slightly more obscure IMHO ;-)

---

Give a man a fish:  <%-{-{-{-<

See the appropriate FAQ: How do I sort a hash (optionally by value instead of key)?

#!/usr/bin/perl
use strict;
use warnings;

my %hashName = (a => 1, b => 2, c => 3, d=>3);

#sort keys by descending order of their value
my @keys = sort {$hashName{$b} <=> $hashName{$a}} keys %hashName;

my $max = $hashName{$keys[0]};

while (my $key = shift @keys)
{
   last if ($hashName{$key} < $max);
   print "$key=>$hashName{$key}\n";
}
__END__
c=>3
d=>3
[download]

use strict;
use warnings;

my %hash_name = ( a => 1, b => 2, c => 3, d => 3 );

my %keys_of_max;
my $key_of_max;
my $numeric_cmp_result;

    $numeric_cmp_result = defined $key_of_max
        ? ( eval join '<=>', map { $hash_name{ $_ } } $_, $key_of_max 
+)
        : 1
    xor $numeric_cmp_result > 0 and %keys_of_max = ( $key_of_max = $_ 
+=> 1 )
    xor ( $numeric_cmp_result or $keys_of_max{ $_ } = 1 )
        for keys %hash_name;

print sort keys %keys_of_max;
[download]

Useless use of logical xor in void context at perlmonks_Max_Value.pl l
+ine 26.
cd
[download]