Short Circuit Operators

[Wilson Mui]

Here was the question:
1 if ((s !=null) | ( i =s.length()))
2 if ((s ==null) | ( i =s.length()))
3 if ((s !=null) || ( i =s.length()))
4 if ((s ==null) || ( i =s.length()))

Which may throw an exception.
The answer is 1,2,4, It's 1,2,3 right?
I mean if s == null, then 3 would be (false) || (exception)...somebody confirm my sanity please.

[chi Lin]

Mui,
Yes, 1 2 3 will throw NullPointerException. but you need to change i=s.length() to something
like s.length()>0 .. so it evalue to boolean on the right side of | or || operator
HTH
[ May 07, 2003: Message edited by: chi Lin ]

[Rory French]

That's a good point chi. None of these statements would even compile, nevermind throw exceptions. Not a very good mock exam question
I really wish that all people who set mock questions would at least compile and run their code before they publish the questions. Otherwise it just causes mayhem and confusion.