PHP Recursive Delete folder

Use PHP to recursively delete the entire folder. If there is anything wrong, please advise us.

/*    ** Traverse Delete Folder     ** @param   $dir   folder to delete folders       */    public function del_dir ($dir) {          $flag  =  $this->is_empty_dir ($dir);         if (  $flag ==false ) {              $DP  = opendir ($dir);             while (false !==  $file  = readdir ($DP)) {                 if ($file  !=  "."  &&  $file  !=  "..."  ) {                     if ( is_dir ("$dir/$file")  ) {                          $this  -> del_dir ("$dir/$file" );                     }else{                         unlink ("$dir/$file");                     }                 }                 }             closedir ($DP);             rmdir ($dir);        }else{          &nbsP;  rmdir ($dir);        }    }     /*    ** determine if the folder is empty     ** @param   folder to be judged      */    public function is_empty_dir ($dir) {          $flag  = true;        if (  Is_dir ($dir)  ) {             $DP  =  Opendir ($dir);             while (false !==   $file  = readdir ($DP)) {                 if ($file  !=  "."  &&  $file  !=  "..") {                      $flag  = false;                }             }             return  $flag;        }else{             echo  "Not dir";         }    }

PHP Recursive Delete folder