You had a few simple errors. This works: 

use Digest::MD5 qw(md5_hex);
use strict;
use warnings;

my $secret = "applepie";

sub get_md5
{
    md5_hex("$secret" . "$_[0]")
};

my @array     = qw(foo bar baz);
my %md5_hash_broken  = (map {&get_md5($_) => $_} @array);

my %md5_hash = ( &get_md5('foo')  => "foo",
                 &get_md5('bar')  => "bar",
                 &get_md5('fubar')  => "baz",
               );

my ($x, $y);
while (($x, $y) = each %md5_hash)
{
    print "$x => $y\n";
}

[download]

The errors (see my changes):

In reply to Re: Creating a hash with key generated by a sub? by steves
in thread Creating a hash with key generated by a sub? by smullis

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