aspose file tools*
The moose likes Programmer Certification (SCJP/OCPJP) and the fly likes concept of method overriding Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Spring in Action this week in the Spring forum!
JavaRanch » Java Forums » Certification » Programmer Certification (SCJP/OCPJP)
Bookmark "concept of method overriding" Watch "concept of method overriding" New topic
Author

concept of method overriding

Sandeep Tyagi
Greenhorn

Joined: Mar 07, 2006
Posts: 3
why we can't use narrowing method in sub class on the case of method overriding
Thanks in advance

with Regards
Sandeep Tyagi
sandeep_pura@yahoo.com
+919811903737
0124-4382173
fred rosenberger
lowercase baba
Bartender

Joined: Oct 02, 2003
Posts: 11406
    
  16

i think it is because of polymorphism...

say you have a ClassA, with a public doSomething() method.

now, ClassB extends ClassA. say you could make B's doSomething() private.

now you make a collection of ClassA. you get a ClassB object, which you can put into the collection, since a ClassB is a ClassA.

now you iterate through the collection, calling doSomething() on every object. when you get to that ClassB, you're gonna have a problem...


There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: concept of method overriding