So there’s no specific lab questions?
Is pixLab one of them? I did it in class but am not sure if it’s part of the curriculum.
Can someone please explain to me how to do number 14 from the multiple choice on the college board site
http://media.collegeboard.com/digitalServices/pdf/ap/ap-computer-science-a-course-description-2014.pdf
Barron’s review book has magbie lab, the elevens lab and the picture lab btw
Here is the problem:
- Consider the following method.
/** @param x an int value such that x >= 0
*/
public void mystery(int x)
{
System.out.print(x % 10);
if ((x / 10) != 0)
{
mystery(x / 10);
}
System.out.print(x % 10);
}
Which of the following is printed as a result of the call mystery(1234)?
(a) 1234
(b) 4321
© 12344321
(d) 43211234
(e) Many digits are printed due to infinite recursion.
What you’re probably missing is that mystery() calls itself inside of itself. That’s what my classmates didn’t get. Basically, it starts by printing out 1234%10, or 4. Then, since it is bigger than 10, it runs the if statement, and gets to “mystery(x/10)”, which is in this case mystery(123). So then it starts to run mystery(123), leaving the rest of mystery(1234) for once it finishes up mystery(123). mystery(123) first prints out 123%10, or 3, then runs mystery(12). This prints out 12%10, 2, then runs mystery(1), which prints out 1%10, which is 1, then doesn’t run the if statement, and then gets to the next print(1%10), printing out 1 again. And now, since mystery(1) is completed, the program can now go about finishing mystery(12),mystery(123), and mystery(1234), in that order, from where it left off. mystery(12) finishes up with printing 12%10 again, then goes to mystery(123), which finishes by printing 123%10 again, then it finally finishes the original method, mystery(1234), by printing 1234%10.
Hahah its kinda complicated to explain
BTW this prints out 43211234, which is D
Also, from the AP Website: “The 2015 AP Computer Science A Exam will not have specific questions that focus on the new AP Computer Science A labs and will continue to assess the concepts and skills outlined in the Course Description. In addition, there will no longer be any GridWorld case study questions. A practice exam is available for teachers through their AP Course Audit accounts.”
– http://apcentral.collegeboard.com/apc/public/courses/teachers_corner/4483.html
So the Free Response will not be about the Magpie, Picture, or Elevens Lab.
Thank you!
Any last minute practice tests that I should do? I’m doing pretty well on the multiple choice, do you guys think the ap cs mc will be as easy as the sample ones?
Which one are you doing? There are 25 Sample MC on the College Board website, if you did those, then those are representative of what you’ll see on the actual thing. If you’re doing Barron’s, then it’s much harder than the actual one.
Doing the ones on the college board, and they seem a bit too easy, so I am a bit worried. Hm, are there any example barron ones lying around online?
Does anybody know:
If I have a void method that changes something, let’s say it’s called foo and it does some random thing (like increments an integer or swaps two elements in an array)
Sometimes when these void methods are called they don’t actually change anything, when and why does that happen?
I saw something about if passing by value, then it doesn’t actually change the original object as it only works with copies of the original.
And if it’s passing by reference, then the void method actually changes it because it’s working with the actual object?
I don’t know if I’m right or not. I need someone’s help to clarify this.
Thanks!
Yes, if it is passed by reference, then it can be changed. Otherwise, it won’t be changed.
nvm found answer
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@skieurope When you say not to be discussed at all, does that refer to specific questions or does it mean we can’t say “Damn that MC was hard”, because, “Damn that MC was hard.”
On the other hand, the FRQ was ridiculously easy, I finished and had time to check over my answers 40 minutes into the 1 hour and 45 minutes we were allotted.
@ChaliTuna “Damn that MC was hard” is acceptable. 
Sorry you found it hard.
Usually, “Damn that MC was hard” isn’t a problem, because you’re not discussing the particular content of the questions. “Damn, that MC question that asked which ninja was better than the others” is more problematic, because now you’re starting to talk about the questions themselves. “Damn, does anyone remember the answer to question 5?” is going to be a big problem.
[Disclaimer: I have no idea if any of the questions talked about ninjas …]
The MC had a couple of challenging problems but overall I think it was very fair, almost like college boards review
The frqs were “easy” but there was something about them. I took my time and had time to review them and what not but you never know.
Okay, okay I apologize for pasting those links here. I just assumed it was okay because I’ve seen so many other threads link to docs and stuff.
Anyways, I thought everything was overall easy. Not a lot of hard or confusing questions at all.
I found the MC to be very difficult; I didn’t complete it in time.
The FRQs were easy except for one section which was rather vague