• 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

InstanceOf Doubt.

 
Ranch Hand
Posts: 509
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Source: http://www.go4java.20m.com/mock1.htm
Here the answer is null,false,false.But null IS-A Object, then why is the answer false?

1 class AA{}
2 class BB extends AA{}
3 class Q6
4 {
5 public static void main(String arg[])
6 {
7 AA a=null;
8 BB b=(BB)a;
9 System.out.println(b);
10 System.out.println(b instanceof BB);
11 System.out.println(b instanceof AA);
12 }
13 }
 
Sheriff
Posts: 9708
43
Android Google Web Toolkit Hibernate IntelliJ IDE Spring Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
null instanceof any type will always result in false. You can read the Java Language Specification for that...
 
Java Cowboy
Posts: 16084
88
Android Scala IntelliJ IDE Spring Java
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator

Originally posted by Abhi vijay:
But null IS-A Object...


No, null is not an object in Java. Where did you hear or read that null is an object?
 
Don't get me started about those stupid light bulbs.
reply
    Bookmark Topic Watch Topic
  • New Topic