一个php截取指定字符串其间的字符串的类

?

class get_c_str {var $str;var $start_str;var $end_str;var $start_pos;var $end_pos;var $c_str_l;var $contents;function get_str($str,$start_str,$end_str){   $this->str = $str;   $this->start_str = $start_str;   $this->end_str = $end_str;   $this->start_pos = strpos($this->str,$this->start_str)+strlen($this->start_str);     $this->end_pos = strpos($this->str,$this->end_str);   $this->c_str_l = $this->end_pos - $this->start_pos;   $this->contents = substr($this->str,$this->start_pos,$this->c_str_l);   return $this->contents;}}?>

<?php$get_c_str = new get_c_str;echo $get_c_str -> get_str('[123456789]','[',']');?>