<?phpclass C { function thisAsVariableVariable() { //$this; // Uncomment to change behaviour. $thisName = 'this'; var_dump($$thisName); } function thisInGetDefinedVars() { //$this; // Uncomment to change behaviour. var_dump(get_defined_vars()); } }$c = new C;$c->thisAsVariableVariable();$c->thisInGetDefinedVars();?>@@Output with //$this commented out:Notice: Undefined variable: this in %s on line 6NULLarray(0) {}@@Output after uncommenting $this:object(C)#1 (0) {}array(1) { ["this"]=> object(C)#1 (0) { }}