浅析PHP的静态成员函数效率更高的原因

<?php // php静态方法测试
header('Content-Type: text/html; charset=utf-8');
class xclass{
     public static $var1 = '1111111111111111';
     public $var2 = 'aaaaaaaaaaaaa';
     public function __construct()
    {
         $this -> var2 = 'bbbbbbbbbbbbbbbb';
         }
     public static function secho1()
    {
         echo self :: $var1 . '<hr />';
         }
     public function secho2()
    {
         echo $this -> var2 . '<hr />';
         }
     public function secho3()
    {
         echo '<hr />';
         }
     }
 xclass :: secho1();
 xclass :: secho3();
 echo "------------------------------<br />";
 $xc = new xclass();
 $xc -> secho1();
 $xc -> secho2();
 ?>