Zaxo has pointed you in the right direction, but if for any means, if you need 'modular sugar',you can use something like this with better design.

package Hash;
sub new {
    my $class = shift;
    my $self = {};
    bless $self,$class;
}

sub addKey {
    my $self = shift;
    my $key = shift;
    $self->{$key};
}
sub printKeys {
    my $self = shift;
    foreach (keys %{$self}){
    print "$_\n";
       
    }
}
sub addValues {
    my $self = shift;
    my $key = shift;
    push @{$self->{$key}}, @_;
}
sub printValues {
    my $self = shift;
    my $key = shift;
    print "$key\t";
    foreach (@{$self->{$key}}){
        print "$_\t";
    }
    print "\n";
}
package main;

my $hash = new Hash;
$hash->addKey('fruit');
$hash->addValues('fruit', 'apple');
$hash->addValues('fruit','orange');
$hash->printValues('fruit');
$hash->addKey('operating system');
$hash->addValues('operating system', 'Linux','Windows XP');
$hash->printValues('operating system');
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