get_object_vars ( $object);

<?php
   class Point2D {
      var x,y;
      var label;

      function Point2D(x, y) {this->x = x;this->y = y;
      }

      function setLabel(label) {
         this->label =label;
      }

      function getPoint() {
         return array("x" => this->x, "y" =>this->y, "label" => this->label);
      }
   }p1 = new Point2D(1.233, 3.445);
   print_r(get_object_vars(p1));p1->setLabel("point #1");
   print_r(get_object_vars($p1));
?>

Array (
   [x] => 1.233
   [y] => 3.445
   [label] =>
)
Array (
   [x] => 1.233
   [y] => 3.445
   [label] => point #1
)