Using the following code (which someone may do accidentally):

$myarray = array("X" => "A", "Y" => "B", "Z" => "C");
foreach($myarray as $key->$value) {
  ...
}

causes PHP (on each iteration) to create an object $key with the value of the current array element in a property with a blank name (because $value has just been created, and is therefore empty).

The following var_dump() output illustrates:

object(stdClass)(1) {
  [""]=>
  string(1) "A"
}

The creation of objects with blank property names seems like it shouldn't be possible (even unintentionally)!