This question is discussed at length in the excellent Perl Best Practices book in the third item of Chapter 9, "Argument Lists: Always unpack @_ first". Notice that this chapter is available free online as the book's sample chapter.

In this item, TheDamian argues that either version is acceptable, with the shift-based version preferred when one or more arguments needs to be sanity checked or documented with a trailing comment. The most important thing though, is to unpack them at the start of the subroutine and to avoid accessing them directly as $_[0], $_[1] etc.

In reply to Re: shift vs @_ by eyepopslikeamosquito
in thread shift vs @_ by Zadeh

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