Java Interview questions on exceptional handling

1.)What happens if main() is written with out String args[]?

--The code compiles but JVM cannot run it,as it cannot see the main() with String args[]

2.)What are checked exceptions?

--Exceptions that are checked by compiler at the compilation time are called as checked exceptions.

3.)What are unchecked exceptions?

--Exceptions that are checked by JVM are called as unchecked exceptions.

4.)What is Throwable?

--Throwable is a class that represents  all errors and exceptions that occur in java

5.)What is the superclass for all exceptions?

--Exception is the superclass for all the exceptions.

6)What is the difference between exception and an error?

--Exception is a situation which can be handled using try catch
--Error cannot be handled by the programmer and leads to abnormal program termination.
    Ex: OutOfMemory 

7)Difference between throws and throw?

--throws clause is used when the programmer does not want to handle the exception and throw it out of method.

--throw clause is used when the programmer wants to throw an exception explicitly and wants to handle it using catch block.

8)Can we rethrow an exception??
--Yes ,we can rethrow an exception from catch block to another class where it can be handled

Points on exceptional handling

•  Exceptions  can be handled using try and catch blocks.
• A try block can be followed with any number of catch blocks.
• Statements are not allowed in between try and catch blocks
• It is possible to handle multiple exceptions using  multiple catch blocks
• Catch block cannot  exist independently ..it should be preceded with a  try block whereas try block need not be followed compulsorily by catch block ,a finally block may follow it.
•  Nested try blocks are supported in java