Paul Anilprem

The 1Z0-815 exam doesn't exist anymore. For Java 11, there is only one exam now - 1ZO-819. You may check the topics covered in this exam here.

You may want to check out this article on Precedence, Associativity, and Evaluation order in Java as well. It covers everything you need for the exam.

There is a review screen in the real exam as well as in our simulator that shows the status of each question in a list. You can click on any question in that list to go to that question.
To go to this screen, just click on Review button on bottom right corner of the question view.

You can't take a bathroom break, can't be seen mumbling or talking to yourself, can't eat, and can't use a pen/paper to write. These are the top reasons why some people prefer to take the exam at the center instead of at home.

Scheduling is online and slot avalability depends on how busy they are on that particular day/time. Usually people are able to schedule a slot for the next day or a day after. Just try scheduling it and you will know.

You might want to check out this at home exam experience for more details.

That really depends on what you are expecting from the certification. Meaning, are you looking for job, are you trying to keep yourself technically updated, or are you required to be certified by your employer, etc. If you provide a little background, I am sure people here will be able to give you a good answer.
You may also go through this article comparing 811/808/819 certifications as a start.

We routinely get requests for help from students while solving mock questions where an IDE is the culprit for causing confusion. Check out the links on this page to see the sort of problems newbies may face while using IDE for certification exam preparation.

Yes.
The attached image highlights a few more things that you need to know about the Java certification exam.

Jesse Silverman wrote:others disagree and say avoid re-taking the same questions too many times like the plague

One may have to resort to retaking the same questions if they run out of new questions but with so many mock exams available, there is really no point in retaking. One would be better off using their time attempting new questions.

Instead of retaking the test, we highly recommend analyzing the test that one has just taken. Checking explanations and understanding why they got a question wrong is very important for improving the score on the next (unseen ) test.

We recommend that one should definitley pass at least one mock test in the first attempt before scheduling the real one.

Some people take the same mock test multiple times and then based on that score, which is invariably higher, decide to take the real exam only to get disappointed by the result.

If you follow the suggestion given here, I believe, you will do well on the real exam.

Not very scientific or fool proof, but this is a good indicator of how you might score on the real exam: https://enthuware.com/java-certification-ocajp-8-average-score

No, topic is not mentioned for a question in the real exam.
It is hidden by default on our simulator (desktop application) as well. It also alerts the user that the real exam does not show this information when the user tries to unhide it.

Tim Holloway wrote:"0L" is an implementation-specific numeric value.

Wouldn't you agree that 0L is just a notation for writing a conceptual numeric value in Java code? It is not an actual value of any kind - neither a machine value nor a conceptual value.

Thank you for the kind words, Jesse!
The keyword here, imho, is "say". If you want to say the value, say the value without the L.
If you want to write the value in Java code, then put the L because that is the rule of the language (that long values have to be written with the suffix L).

Having said that, we haven't seen anyone getting a question where you have to differentiate between 0 and 0L in past several years. I keep a watch on such things (forums and talking to our exam trainees) and I haven't heard it from any candidate.

HTH,
Paul.

Actually, the JLS in section 4.1 says so clearly:

The integral types are byte , short , int , and long , whose values are 8-bit, 16-bit, 32-bit and 64-bit signed two's-complement integers, respectively, and char , whose values are 16-bit unsigned integers representing UTF-16 code units (§3.1).

(emphasis is mine)

So, it is accurate to say that a long variable containing 0 is a series of 64 zeros.

Further, in section 4.2.1, JLS 11 says,

The values of the integral types are integers in the following ranges:
...

So, it is also perfectly accurate to say that the value of a long variable containing 0 is just 0.

Even though the two statements may seem contradictory but they are not. The first one defines the machine view and the second one defines the conceptual/virtual view.

So, I am now of the opinion that the statement "value of a long var containing 0 is 0L" is actually wrong  

Default values of all numeric types is "zeroes in all bits". Obviously, it is not practically possible to type 8, 16, 32 or 64 zeroes to convey the exact type of your variable whenever you want to tell that it holds a 0 value. So, it is correct to say just 0.
However, within Java code, you do need to convey the type information to the compiler and so, you write 0, 0.0, or 0L or 0.0f, depending on the type of the variable you want to assign the value to.

So, the default value of an int (or a long, float, double) variable is indeed zero. But writing int i = 0L; in Java code would be wrong.

No, you don't need to purchase the training. Anyone can take the exam.