Possible Bug or Bad Expectations?

Hi all, I am conflicted as per if what I experience in this code should be throwing a notice in E_STRICT: http://3v4l.org/srm5f <?php error_reporting(E_ALL); $foo = ['bar' => ['baz' => 5]]; $bar = ['box' => 'baz']; // this will Notice: Undefined index: boom var_dump(isset($foo['bar'][$bar['boom']])); Essentially, my expectation is that anything inside an isset() would be immune from notices of undefined indexes, but that is not the case with nested array key lookups. Is this a bad expectation to have? Or should isset() silence the nested undefined index as well? I also realized this has always been the behavior leading me to believe I might have a bad expectation here. In any case wanted to check. Thanks, -ralph