This week's book giveaways are in the AI and JavaScript forums.
We're giving away four copies each of GANs in Action and WebAssembly in Action and have the authors on-line!
See this thread and this one for details.
Win a copy of GANs in ActionE this week in the AI forum
or WebAssembly in Action in the JavaScript forum!
  • 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 all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Bear Bibeault
  • Paul Clapham
  • Jeanne Boyarsky
  • Knute Snortum
Sheriffs:
  • Liutauras Vilda
  • Tim Cooke
  • Junilu Lacar
Saloon Keepers:
  • Ron McLeod
  • Stephan van Hulst
  • Tim Moores
  • Tim Holloway
  • Carey Brown
Bartenders:
  • Joe Ess
  • salvin francis
  • fred rosenberger

Mock Exam Question

 
Ranch Hand
Posts: 85
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator


Consider the above code from Dan Chisholm's site, the answer given is "None of the above"(g).
The question I have is how come it will not generate null pointer exception at 3 when casting cloneable reference to int array when int array is null.

Any answers? Thanks guys!
 
Ranch Hand
Posts: 3271
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
null can really be cast as anything you want. An Object can be null, an array can be null, an ArrayList can be null. Likewise, null can be anything.

You get a NullPointerException when you actually try to access a member of an object that is null, not when you cast null as a different type.
 
Nina Binde
Ranch Hand
Posts: 85
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thank you Corey for correcting my misconceptions!
 
If we don't do the shopping, we won't have anything for dinner. And I've invited this tiny ad:
Java file APIs (DOC, XLS, PDF, and many more)
https://products.aspose.com/total/java
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!