PHP 函数 get_object_vars()

<?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));
?>