php判断字符串

                  
                 结果为1只有数字,2只有字符,3两者都有                $a     =     0     ;      $b     =     0     ;      for     (     $i     =     0     ;      $i     <     strlen     (     $str     );     $i     ++     ) {       $v     =     ord     (     substr     (     $str     ,     $i     ,     1     ));      if     (     $v     >=     48      and      $v     <=     57     ) {       $a     =     1     ; }       else      {       $b     =     2     ; }  }      return           $a     +     $b     ; }     echo      checkVS(     "     sff     "     )     ?>