All completely valid points.

However, assigning to a simple lexical scalar within a map block is dirt cheap both in terms of memory and execution speed. Perl is probably gonna do something like that internally anyway, it just won't have a "name". If assigning a lexical name makes the code more clear, then why not?

In this thread, I think the OP has some confusion about maps and foreach loops. So I showed a couple of ways for each significant loop in the code.