[php] PHP Fatal error: Cannot access empty property

Interesting:

  1. You declared an array var $my_value = array();
  2. Pushed value into it $a->my_value[] = 'b';
  3. Assigned a string to variable. (so it is no more array) $a->set_value ('c');
  4. Tried to push a value into array, that does not exist anymore. (it's string) $a->my_class('d');

And your foreach wont work anymore.