Re^2: gotchas with hash element autovivification (dry)

[tye]

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

More-DRY versions:

if(  exists ${ $rec{NOTE­} || {} }{Nested}  ) {
# or
if(  ( $rec{NOTE­} || {} )->{Nested}  ) {
# or
if(  exist +( $rec{NOTE­} || {} )->{Nested}  ) {

Though, I find that I use those less often to avoid auto-viv and more often to prevent a potential fatal "Can't use undef as HASH ref" (something that I think should at least be turned into just a warning -- since sometimes it is fatal and sometimes it is a silent success, and I'm not even sure what distinguishes between those two behaviors).

[JavaFan]

It's a matter of opinion, but I prefer the simplicity of my suggestion, even if there's repetition. Even though I sometimes use your technique (typically in cases like keys %{$hash{foo} || {}}), I still had to look twice.