How can I swap two Perl variables without using the third?

Question

I want to swap two variables values without using the third variable in Perl, e. g.:

my $first = 10;
my $second = 20;

Please suggest me how

Answer 1

You can write:

($first, $second) = ($second, $first);

(See §3.4 "List Assignment" in Learning Perl, Third Edition.)