If you have trouble understanding the second one, you should look up the phrase "Schwartzian transform", when you have some free time, and read up on the technique. Becomming comfortable with this is something that will help you to think like an advanced Perl programmer. It's not just the technique itself, but the paradigms that it represents, notably, the idea of transforming a list, which is a very generally applicable thing and something Perl is very good for doing, so that it is something every really advanced Perl programmer needs to understand.

However, ad interim, you should use the technique that you understand already.