Need to Return() ?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I was reading through Conway's OOP and remembered something about telling within a sub if it was "expected" to return() a value, and what types. For the life of me, I can't find it again in the book. Can anyone please tell me how this is done, or point me towards a page number? Its not in the glossary or index that I saw..

thanks

Comment on Need to Return() ?

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Re: Need to Return() ? by merlyn (Sage) on Mar 15, 2001 at 08:29 UTC
wantarray -- Randal L. Schwartz, Perl hacker	[reply]
Re: Re: Need to Return() ? by a (Friar) on Mar 15, 2001 at 10:27 UTC
And so others can get the benefit of your wisdom w/o the OOPerl book (but buy it nonetheless, its a great book), pg 34 gives the example: `sub listdir { # do file listing and the: return @missing_files if wantarray(); return $listed_count if defined(wantarray()); carp "subroutine &listdir was called in a void context"; } # sub listdir` [download] The really cool thing here: wantarray returns true if: @missing = listdir(@files); (called in a list context); returns "" (i.e. false but defined) if: $list_count = listdir(@files); (called in a scalar context) and returns undef if: listdir(@files); (called in a void context - get the carp). a	[reply] [d/l]