personel.pm:

package personel;

use Data::Dumper;

sub sortAge {
    $b->[1] <=> $a->[1];
}

return 1;


##</code><code>##

#under test.pl
@age = ( @f1 = (amy,35), @f2=(bill,55), @f3=(george,28), @f4=(jason,71));
@age = sort personal::sortAge(\@age);

##</code><code>##

@age = sort sortAge(@age);

##</code><code>##

@age = ( @f4=(jason, 71), @f2=(bill, 55), @f1=(amy, 35), @f3=(george, 28))

##</code><code>##

my @array = caller;
${$"{array}::b"}->[1] <=> ${$"{array}::a"}->[1]