Unreachable Code

[Tina Tibrewal]

1 public class exception
2 {
3 public static void main(String args[])
4 {
5 System.out.println("A");
6 try
7 {
8 return;
9 }
10 catch(Exception e)
11 {
12 System.out.println("B");
13 }
14 System.out.println("C");
15 }
16 }

Source: http://www.go4java.20m.com/mock1.htm

According to me it should throw unreachable code error during compilation
but the output is A.
Can anyone explain this?

[Tommaso Nuccio]

Hi,

what is the difference between
- Exception
and
- IOException
?

Good luck.

[Omer Haderi]

hi,

that behavior is due to the try-catch block. If exception occurs in the try block then control is moved to the catch block but the catch block does not do much just print out something after the printing statement the program continue execution normally. If you rethrow the exception in the catch block then the last print statement wont be reached and THEN it is a compiler error.

Hope that helps.

cheers.

[Tina Tibrewal]

IOException is a subclass of Exception.

[Tina Tibrewal]

Even in this the last print statement is not reached then
why doesnt it give an error?

[Omer Haderi]

Compiler just does not know what might happened in the try block... There might not be an error (so the method will return), But there may be an exception AND therefor the execution will continue until the end. SO that is not a compile time error.

cheers,

[Tommaso Nuccio]

Originally posted by Tina Tibrewal:
IOException is a subclass of Exception.

Correct.
Which one is checked?

Good luck.

[Tommaso Nuccio]

Dang,

I hate this code snippets that are not formatted.
The catch has a body with a System.out.

Omer is of course correct.

Sorry.

[Henry Wong]

Originally posted by Tommaso Nuccio:
Dang,

I hate this code snippets that are not formatted.
The catch has a body with a System.out.

Omer is of course correct.

Sorry.

Actually, *both* Tommaso and Omer is correct. The reason "C" is reachable is because there is a possibility of an exception occuring. But the reason that an exception is allowed is because Exception includes unchecked exceptions. If the catch was simply an IOException, then the catch block would have been considered unreachable code.

Henry