PHP正则表达式函数 preg_split()

<?php
   $ip = "123.456.789.000"; // some IP address
   $iparr = split ("/\./", $ip);

   print "$iparr[0] <br />";
   print "$iparr[1] <br />" ;
   print "$iparr[2] <br />"  ;
   print "$iparr[3] <br />"  ;
?>