Let's Self-Study Comp Sci for 2011-2012!

<p>We finished in February. We’ve been reviewing for a month now</p>

<p>How hard are Barron’s and Litvin practice tests compared to the actual exam?</p>

<p>I took a practise test recently; my only errors were stupid mistakes(forgot array indices start at 0, not 1) and GridWorld…I’m so glad that they’ll give us source code on the exam.</p>

<p>Hey Guy’s can anyone help me with a Barron’s problem on Chapter 3 Inheritance and Polymorphism question #13. The justification of answer A is confusing? How is parrot2 a bird? Can you even change the type variable parrot to bird??? And I thought you could down-cast any variable as long as it dictates a superclass to subclass notion?</p>

<p>Is Barron’s just overdoing it, and do I have to know this for the exam?</p>

<p>Parrot2 is a bird because it is a parakeet. More importantly, the print name method is automatically extended verbatim into the subclasses, so you can still use it for parrot2.</p>

<p>omg its on tuesday11111</p>

<p>Even though I enjoy and plan to major in CS, I am really having a hard time caring about this exam. Must be senior laziness.</p>

<p>I feel like there’s nothing left to study… I went through Barron’s and the past three years’ FRQ. Is there any other place to get good MC practice? I’ve done the 2008 practice test as well as the 20 MC questions in the APCS syllabus.</p>

<h1>13 on Chapter 3 Barron’s:</h1>

<p>Parrot is extending Bird which means it can use any of the methods in Bird by default just by calling the method. In printname it’s passed a Bird and since Parrot extends Bird, Parrot is-a Bird so parrot2 is fine to be used in that method. Then printBirdCall passes (Parrot)bird2 and it can be casted as a Parrot since it was initialized as “Bird bird2 = new Parrot()” </p>

<p>B is bad because you can’t cast a Bird as a Parrot that was initialized as it was.
C is bad because printBirdCall wants a Parrot and you’re passing a Bird (has to be casted as a Parrot)
D is bad because you can’t cast a Bird initialized like that as a Parakeet.
E is bad because you can’t cast a Parakeet as an owl.</p>

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<p>Nice resource, but keep in mind:</p>

<ol>
<li> GUI, Threading and FileIO are not tested.</li>
<li> Not every ArrayList method will be tested.</li>
<li> There’s nothing on Gridworld in this book and about 25% of the test is.</li>
<li> Most of the collections chapter is overkill.</li>
<li> BigO is not on the test… (it was on the old AB test)</li>
</ol>

<p>

I’ve looked over the Stanford Curriculum. It’s a nice into to APCS, but I’d say that is only covers 60% of the APCS material. Make sure you also download the Gridworld student manual and work all of those problems out.</p>