PHP实现获取文件后缀名的几种常用方法

方法1：function get_file_type($filename){ ?$type = substr($filename, strrpos($filename, ".")+1); ?return $type;}方法2：function get_file_type($filename){ ??$type = pathinfo($filename); ??$type = strtolower($type["extension"]); ??return $type;}方法3：function get_file_type($filename){ ????$type =explode("." , $filename); ??$count=count($type)-1; ??return $type[$count];}