Exception questions

[Henry Zhi Lin]

Hi guys,

The following question is from SCExamLab exame Practice 2, question 35.

Look at the following class definitions. Which of the following statement are true? )(Choose four)

  class Expn1 extends RuntimeException{}
  class Expn2 extends Exception{}
  class Expn3 extends Throwable{}
  class Expn4 extends Object{}  

[A] Expn1 is a checked exception.
[B] Expn1 is an unchecked exception.
[C] Expn2 is a checked exception
[D] Expn2 is an unchecked exception
[E] Expn3 is a checked exception
[F] Expn3 is an unchecked exception
[G] Expn4 is a checked exception.
[H] Expn4 is an unchecked exception
[I] Expn4 cannot be used as an exception

My answer are B C F I, but the answer from the test are B C E I.

My question is how come Expn3 is a chcked exception here? Can anyone give me an explaination?

[Kenneth Lomvey]

Try to compile the following program:

class CEx{
public static void main(String args[]){
throw new Throwable();
}
}

You cannot compile this, because java.lang.Throwable is a checked exception. only java.lang.RuntimeException and sub classes are unchecked.

[Abhi vijay]

but exceptions are objects, then why I is the correct answer?

[Ankit Garg]

but you can use instances of classes which are sub-classes of Throwable in the throws and throw clause...

[Kenneth Lomvey]

Originally posted by Abhi vijay:
but exceptions are objects, then why I is the correct answer?

To use something as an excepion, it MUST be a sub-class of java.lang.Throwable.