286                                                     10. 

   
ps -> print() ;

 student: : print ().  ps    s 
student.    

ps = pgs = &gs;

      grad_student.  ps -
   . 

pgs -> print() ;

 grad_student: :print().  pgs    
grad_student,         - 
 .   

ps -> print() ;

 student: : print ().  ,       -
 gs  grad_student    :   10.4, 
,  . 289  ,    -
 ,        ,  -
  ,    .'

10.3.   :   

      ,   ISA.
        ,   -
       . 
     LIKEA ().   -
  ,    .
       
    .   (   -
)     ,     -
,   .      -
  (    )  .

      ,     .
,        -
     (.  9.6,  
 ,  . 255).       
  .       
 ,   .   -
 ;  ,  ,    , -
 ,    .

'    ( )   .
   ,      (  ) -
   ( ). ,    -
    ,   ,     (),
  ,         ().  . .