Finally block is optional??

Question

I want to know if finally block is optional? I tested this myself, and
the following yield the same output.
void f()
     try
     { //code1
     catch()
     finally
     { //code2
void f()
     try
     { //code1
     catch()
     //code2
please advise. thanks!!

Answer 1

I'm not sure what you're asking, and your sample code tells us almost nothing, but I'll take a guess.
You're thinking finally doesn't do anything, because you can just put the code after the catch block, right?
Here's some more realistic code: void foo() throws IOException {
    InputStream ins = null;
    try {
        Bar bar = new Bar(); // this might throw BarException
        ins = bar.getAnInputStream();
        ins.read(); // etc.
        // do stuff with what we read from ins
    catch (BarException exc) {
        // log, handle, whatever
    finally {
        // cleanup, for example ins.close();
    // OR we could cleanup here, you think, right?
} If the try block completes without any problems, or if a BarException is thrown and we don't rethrow anything from the catch block, then, yes, you could put the cleanup after the finally block.
However, what happens if bar.getAnInputStream() returns null? Or if there's an IOException creating or reading the stream? In that case, we jump out of our try block as soon as the exception occurs--the IOException or the NPE if we try to call read() on a null stream reference.
In this case the try block stops what it's doing and control passes to the finally block, after which we leave the method (well, leave the try statement for the next enclosing try, but there isn't one in this method, so we leave the method).
If we throw an uncaught exception (anything other than IOE, in this example) or even if we call return from inside the try block, the finally block will always be executed. The code following the finally block won't be executed in these cases.
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