mySub(
    opt1 => $value1
    opt2 => $value2
    opt3 => $value3
)

##</code><code>##

#!/usr/bin/perl
use strict;

hash(
    uno => 'one',
    dos => 'two',
    tres => 'three',
);

sub hash {
    my $param = @_; 
    print $param->{uno}, "\n";
}

##</code><code>##

~/programming/perl/oo$ ./test.pl 
Can't use string ("6") as a HASH ref while "strict refs" in use at ./test.pl line 7.