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;
...

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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.

In reply to Re: my $a outside sort block incompatibility by tilly
in thread my $a outside sort block incompatibility by Anonymous Monk

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