• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Jeanne Boyarsky
  • Ron McLeod
  • Paul Clapham
  • Liutauras Vilda
Sheriffs:
  • paul wheaton
  • Rob Spoor
  • Devaka Cooray
Saloon Keepers:
  • Stephan van Hulst
  • Tim Holloway
  • Carey Brown
  • Frits Walraven
  • Tim Moores
Bartenders:
  • Mikalai Zaikin

Doubt

 
Ranch Hand
Posts: 362
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hi,

Why does line 3 cause Class Cast Exception where as line 4 doesn't

Thx
[ April 06, 2004: Message edited by: Mary Cole ]
 
Ranch Hand
Posts: 75
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
In line 3 u r trying to cast a base class object to a derived class,which causes the compile time error,as this does not make any sense.(Only derived class objects can be casted to base class objects.
In line 4 though u r trying to cast the interface reference to the base class,the underlying object to which the reference i is pointing is a base class object,so casting a base class object to itself does not cause a compile time error.
 
If you believe you can tell me what to think, I believe I can tell you where to go. Go read this tiny ad!
a bit of art, as a gift, that will fit in a stocking
https://gardener-gift.com
reply
    Bookmark Topic Watch Topic
  • New Topic