Are there conditions in which you can still create autovivified hash keys with undefined values that you never intended to do? And what is the way to avoid that now with current versions of Perl?
Nothing has changed in this aspect in the 21st century. $rec{NOTE} did not autovivify in 5.005, and it doesn't in 5.15.9. exists $rec{NOTE}{Nested} autovivified $rec{NOTE} in 5.005, and it does so in 5.15.9.

It probably wasn't different pre-5.005, but I don't have such a perl currently available.

If you want to avoid it? Use long hand: 

if ($rec{NOTE} && exists $rec{NOTE}{Nested}) {
    ...
}

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In reply to Re: gotchas with hash element autovivification by JavaFan
in thread gotchas with hash element autovivification by raybies

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