Others have already answered your more immediate question, but from the way you asked, it looks like you may have a misconception about how subroutine parameters work in the first place.

All that passing parameters to a subroutine call does, is to make those values available to the subroutine in the special @_ array.
It does not automatically make each parameter a variable inside the subroutine, and in fact it won't have any effect at all if the subroutine does not choose to look at the contents of @_.

Often, "looking at the contents of @_" is done implicitly using calls to shift, hence the  my $candidate = shift; in the above answer.

If you need more explanation, please read perlintro#Writing-subroutines.

In reply to Re: Problem with parameters in subroutines by smls
in thread Problem with parameters in subroutines by aatrox

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