package personel;

use warnings;
use strict;


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

sub cmpAge1 { $main::b->[1] <=> $main::a->[1]; }
sub cmpAge2 { $::b    ->[1] <=> $::a    ->[1]; }

sub cmpAge3 {  # slower
    my $callingPkg = caller;
    no strict 'refs';
    ${"$callingPkg\::b"}->[1] <=> ${"$callingPkg\::a"}->[1];
  # ${"${callingPkg}::b"}->[1] <=> ${"${callingPkg}::a"}->[1];  # also works
    }


return 1;