About Question enthuware.ocpjp.v7.2.1417 :

[renatumb]

Why does it return

12 ""

Because the last letter is "l" so when it returns

11 ""

there is no anything else to return

[admin]

That's a good question and I am not really sure why
The javadoc says, the start method returns the "start index of the previous match" and "The index of the first character matched".
My guess would be that it is trying to return the index of the boundary.
-Paul.

[sir_Anduin@yahoo.de]

i dont understand, if it says:

find()
Attempts to find the next subsequence of the input sequence that matches the pattern.

why does it find anything after "wow"?

nothing after it matchers the pattern [wow]*

[admin]

That is indeed a mystery to me. It doesn't print anything in Java 8. But the answer is correct for Java 7.

-Paul.