Hello maciej, and welcome to the Monastery!

Expanding on the advice from Anonymous Monk, here is one way to implement the solution:

#! perl
use warnings;
use strict;

my %hash = (1 => 8, 2 => 6, 3 => 3, 4 => 7);
my $highest_value;
my $highest_key;

while (my ($key, $value) = each %hash)
{
    print "$key key has value $value\n";

    if (!defined $highest_value || $highest_value < $value)
    {
        $highest_key   = $key;
        $highest_value = $value;
    }
}

print "The element with key $highest_key " .
      "has the highest value $highest_value\n" if defined $highest_key
+;
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Output:

12:36 >perl 591_SoPW.pl
4 key has value 7
1 key has value 8
3 key has value 3
2 key has value 6
The element with key 1 has the highest value 8

12:38 >
[download]

Note that this uses < to compare values numerically. To compare the values as strings, you would need to use lt instead:

if (!defined $highest_value || $highest_value lt $value)
[download]

Hope that helps,

Update: ++Anonymous Monk for the syntax below: it’s both simpler and more efficient. Confession: I had to re-read the documentation for each to verify that it Does the Right Thing here (it does). :-)