Question

When accessing class members from member functions, am I obligated to use $this? Or I can just mention member names?

Answer 1

Using $this differentiates between object members and variables that are simply local vars. e.g.

object x {
   public $z = 'hello';
   function y() {
      $z = 'there';
      echo $z; // there
      echo $this->z; // hello
   }
   function z() {
       echo $z; // undefined variable/warning/error.
   }
}