my %sortfkt = (
        "item"          => \&numerical,
        "name"          => \&string,
        "age"           => \&numerical,
        "height"        => \&numerical,
        );

##</code><code>##

sub string {
	return $_[0] cmp $_[1];
}

sub numerical {
	return $_[0] <=> $_[1];
}

##</code><code>##

sort { &{$sortfkt{$orderby}}($hash{$a}{$orderby}, $hash{$b}{$orderby}) } keys %hash

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

my %sortfkt = (
		"item"          => \&numerical,
        "name"          => \&string,
        "age"           => \&numerical,
        "height"        => \&numerical,
        );

my %item1 = (
        "item"          => 1,
        "name"          => "smith, john",
        "age"           => 25,
        "height"        => 1.80
        );

my %item2 = (
        "item"          => 2,
        "name"          => "jones, bob",
        "age"           => 26,
        "height"        => 1.70
        );

my %item3 = (
        "item"          => 3,
        "name"          => "arrang, eliee",
        "age"           => 27,
        "height"        => 1.75
        );

my %hash;
$hash{1} = { %item1 };
$hash{2} = { %item2 };
$hash{3} = { %item3 };

my $orderby = "name";

foreach my $id (sort { &{$sortfkt{$orderby}}($hash{$a}{$orderby}, $hash{$b}{$orderby}) } keys %hash) {
  print "$hash{$id}{'item'} - $hash{$id}{$orderby}\n";
} # end-foreach

sub string {
	return $_[0] cmp $_[1];
}

sub numerical {
	return $_[0] <=> $_[1];
}