How RuntimeException is unchecked while Exception is checked?

[Vivek Hari Narayanan]

Dear All CodeRanch Members,
This is my first post and i hope its not a stupid/repeated question.

According to API RuntimeException extends Exception. When we throw new RuntimeException(); we need not declare or handle it but when we throw new Exception(); we have to handle or declare it.
How is it possible because when we create our custom exception(i.e by extending Exception) it also becomes checked but why is RuntimeException unchecked even after extending Exception?
Is RuntimeException specially handled by JVM or there is some other reason?

Regards,
Vivek

[ramesh maredu]

Hi Vivek,

Welcome to java ranch.

I think the compiler treats the exceptions differently when they extend Exception directly. As the checked exceptions are meant to be handled you will be forced to catch them or let the caller method handle them. In case of run time exceptions then compiler don't enforce any rule because they are not meant to be handled (probably user may not be able to do anything if they occur, the better way would be make sure run time exceptions may not occur).

[Vivek Hari Narayanan]

ramesh maredu wrote:Hi Vivek,

Welcome to java ranch.

I think the compiler treats the exceptions differently when they extend Exception directly. As the checked exceptions are meant to be handled you will be forced to catch them or let the caller method handle them. In case of run time exceptions then compiler don't enforce any rule because they are not meant to be handled (probably user may not be able to do anything if they occur, the better way would be make sure run time exceptions may not occur).

Hi Ramesh,
Thanks a lot i finally got my doubts cleared