laptop:~> perl -wle 'print "TrUe" if undef == 0'
Use of uninitialized value in numeric eq (==) at -e line 1.
TrUe

##</code><code>##

laptop:~> perl -le 'print "TrUe" if "foo" == 0'
TrUe
laptop:~> perl -le 'print "TrUe" if "foo"'
TrUe