Proveit.com C++ test

Has anyone taken the C++ test on proveit.com ? I've done it a few times, and there are always questions that I get wrong, but I can't help but assume it's the site and not me. The only example I can think of off the top of my head (its been a while) is

What is the value of x after the operation?

int x = 5;
++x;

And it gives a few answers, one of which being 6. I don't see how it could be anything but. Just to be sure I would compile the code and still get 开发者_运维百科the same answer, but the test would tell me I'm wrong. Wondering if anyone has any experience with this test/site.

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Perhaps the test read what will this output:

int x = 5;
std::cout << x++;

And the question was:

What will be the output?

Because when you do this x will change value but will display 5 from cout because x is incremented after the original value of x is displayed. Otherwise, it should equal 6 in your case. (You said it had been a while...)

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Strictly speaking this is implementation dependent, because there might an overflow here. But for all practical purpose, yes, the value of x should be 6 when the code is done execution.

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You probably have an answer by now, but hopefully this will help someone else. Depending on how the question is stated you may have got the wrong answer:

int x = 5;
cout << x++ << endl;
cout << x << endl;

would display 5 and 6 because x is incremented AFTER it has been outputted. However,

int x = 5;
cout << ++x << endl;
cout << x << endl;

would display 6 and 6 because x is incremented BEFORE it has been outputted.