exists is a better test for hash and array elements, and will not auto-vivify them. 
perl -le '
$a[10] = 1;
if (exists $a[2]) {
  print "how did that get there?\n";
} else {
  print "a[2] does not exist\n";
}
'
a[2] does not exist

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In reply to Re: Erroneous defined detection of array elements by keszler
in thread Erroneous defined detection of array elements by Anonymous Monk

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