PHP截取接口

public function common_substr($str, $start, $length, $encoding){ //截取方法

           /*mb_substr( $str, $start, $length, $encoding )

              $str，需要截断的字符串

              $start，截断开始处，起始处为0

              $length，要截取的字数

              $encoding，网页编码，如utf-8,GB2312,GBK 

              */

           return mb_substr( $str, $start, $length, $encoding );

     }