Re^4: Perl Style: Is initializing variables considered taboo?

[ait]

and please be careful not to return undef to "explicitly" return false.

Many people use return undef to indicate false in the execution of a sub, but it's likely I'm really not getting what you mean by "explicitly":

perl -e 'foreach (@INC){print "$_\n" unless $_ eq q{.}}' | xargs grep 
+-R "return undef" | wc -l<br>
1752

Subs return lists, so what you are actually doing is returning a one-element list instead of an empty one. I.e. @array=func(); Using a blank return is the same like return (); and won't byte you in list context but in scalar context the variable will be undef anyway.

I have found it wise to always return an explicit value, to avoid a potential bite or 'feature' of the "last expression", and have till now, used undef to indicate falseness and failure, and a defined value or "1", to indicate trueness/success.

As you point out, it is often overlooked that Perl returns lists and as a result most of the time subs are evaluated in scalar context; in OO code it's customary to return a single ref to an object or undef on failure. So what exactly do you mean by not returning undef to "explicitly" return false.