posted 7 years ago
Hi
Answer is little incorrect.
It's written: "If the submit() method had been used instead of execute(), then C would have been the
correct answer, as the output of submit(Runnable) task is a Future<?> object which can
only return null on its get() method."
Lambda give us submit(Callable) not Runnable. I have changed execute to submit and got 0 1 2 3 4