I was quite surprised to find that \() (ref to an empty list) and [] (ref to an empty array) are not the same. I can understand that an empty list can be used to initialize both an empty array and an empty hash, so there must be a difference, but it turns out that the empty list becomes a ref to 'undef', and not (as I expected) a ref to something empty: 
use Data::Dumper;
my $aap = \();
my $noot = [];
print Dumper($aap);  
print Dumper($noot);
__DATA__
$VAR1 = \undef;
$VAR1 = [];

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Can anybody explain the logic behind this or point me to the relevant piece of documentation (I've searched, but don't know what to look for exactly), so I don't fall into similar traps in the future?

Edit by tye, put [] in CODE tags so it doesn't "disappear"

In reply to difference between \() and [] by eXile

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