Yet another way to do it is to use a sort routine with a ($$) prototype on it.

...
my $a = "whatever";
my $sort_sub = sub ($$) { $_[0] <=> $_[1] };
@arr2 = sort $sort_sub @arr1;
...
[download]

The main reason to use the ($$) prototype in a sort routine is the case where you may be defining the sort routine in one package, and then calling sort in another.