use strict;
use warnings;
use Data::Dump::Streamer;

my %hash = (a => 1, b => 2, c => 3);
printHash (%hash);

sub printHash {
    my %subHash = @_;
    
    print "$_ => $subHash{$_}\n" for keys %subHash;
}

##</code><code>##

c => 3
a => 1
b => 2

##</code><code>##

...
printHash (\%hash);

sub printHash {
    my ($subHash) = @_;
    
    print "$_ => $subHash->{$_}\n" for keys %$subHash;
}