aspose file tools
The moose likes Beginning Java and the fly likes Understanding instanceof operator Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "Understanding instanceof operator" Watch "Understanding instanceof operator" New topic
Author

Understanding instanceof operator

Ethan Bosco
Greenhorn

Joined: Nov 01, 2004
Posts: 15
From K & B book pg : 159 instanceof operator

Given

interface Face{}
class Bar implements Face{}
class Foo extends Bar{}

there is a table which says
----------------------------------------------------------------------
First Operandinstanceof OPerandResult
-----------------------------------------------------------------------
Foo[]Foo, Bar, Facefalse
Foo[]Objecttrue
Foo[1]Foo, Bar, Face, Objecttrue

can someone give me some line of code that will validate the above table?

Thanks in advance
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
You can use something similar to the code in this thread.


Ask a Meaningful Question and HowToAskQuestionsOnJavaRanch
Getting someone to think and try something out is much more useful than just telling them the answer.
Ethan Bosco
Greenhorn

Joined: Nov 01, 2004
Posts: 15
Thanks Barry,
I am still unable to understand maybe I should format the table better

my Second attempt, My q esp how Foo[] instance of Foo equals false any code that I can try
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
Ethan Bosco
Greenhorn

Joined: Nov 01, 2004
Posts: 15
Thanks for the code Barry , how about the third row in the table



Thanks again
Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
Now we are in the correct forum:

Barry Gaunt
Ranch Hand

Joined: Aug 03, 2002
Posts: 7729
My apologies, I did not see you were actually trying out the statement, I thought you just wanted me to write the next four lines for you.

The above code compiles and runs for me (java 1.5.0).
 
Don't get me started about those stupid light bulbs.
 
subject: Understanding instanceof operator