AP Computer Science A - Unit 9: Inheritance

Study guide and exam review for Unit 9: Inheritance
APCSA curriculum in Java.
ap csa unit 9
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0:00 Introduction
0:22 Part 1 - Inheriting Methods
4:22 Part 2 - Overriding Methods
7:24 Part 3 - Calling Superclass Methods
11:39 Part 4 - Accessing Private Fields
13:31 Part 5 - Polymorphism
17:47 Part 6 - Constructors in Standalone Methods
22:57 Part 7 - Calling Constructors in a Superclass
26:39 Part 8 - Passing Data to a Superclass Constructor
30:47 Conclusion
Also, check out the College Board Advanced Placement AP Daily Live Review Session.
#Java #JavaTutorial #APComputerScienceA

[@BillBarnum]

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🎧🚀 Fun Sci-Fi Audiobook For Educators: amzn.to/3TItymu 🪐🎧

[@michaellai872]

2hours before the exam and im still trying to cram the whole course.🤣

[@BillBarnum]

Good luck on the test!

[@tedlaned2856]

how was the test?

[@nonlocaldirect42]

Same here lmao

[@Sydney-zq7cx]

same

[@AyaanZaz]

@@tedlaned2856it hasn’t started yet

[@theonlineasian2617]

This Channel is saving me in AP CSA

[@mr.sujithgamingyt507]

thank you so much man i am struggling apcsa since starting of the semester but after watching your videos i made feel so easy and i have my test tomorrow

[@fatimahadi2210]

I love all of your unit videos, you’re the main reason I’m passing csa right now!!!!

[@PancakeTiger358]

Great video! Wish I found these back in the first semester.

[@nigeriancitizen2785]

Same bro 💀

[@byhealer]

This is great!

[@bluesealol]

Your videos are amazing. I understand everything so much clearer now.

[@jiohseo650]

This video was so useful in my preparation for this year’s ap exam!! I had a lot of troubles with understanding the inheritance part but after watching your video I was able to understand the concept clearly. Thank you so much for such a helpful video and keep up on uploading your wonderful lectures! ☺️

[@BillBarnum]

Glad it helped! Good luck on the test!

[@ahmedhazem4721]

i liked the pace!

[@BillBarnum]

Thanks for the feedback.

[@raspberrygamer9675]

Great video!

[@BillBarnum]

Thanks!

[@Soko..]

Hi Mr. Bill I have been using your alice 3 tutorials to get through the AP Computer Science Principles class I have bee taking and they have been extremely helpful. I wanted to ask you a specific question on arrays and user input. I have only been able to demonstrate and figure out one way to incorporate user input in an array. If you can answer what are some ways you can incorporate user input into an array. Thank you so much for the help and I will keep using your videos to get me through AP Computer Science next semester.

[@BillBarnum]

Specifically, what are you trying to do?

[@everythingcoveredff890]

2 Hours left y’all, can’t wait to start studying!

[@FrenchFries879]

Tbh i still didnt get anything and i have a chapter test tmmrw 😢😭😭

[@jeffguy4669]

bruh fax :(

[@up_to_a_million]

The pace was about right

[@sandeeprachapudi]

At 10:00 how does kitt.applybrakes(); call the subclass SelfDrivingCar method applyBrakes();? Shouldn't CountryRoad be a subclass of SelfDrivingCar to do something like that?

[@BillBarnum]

Typically when we create an instance of a class (e.g. Car, SelfDrivingCar, etc.) we do it in a class (e.g. CountryRoad) that ISN'T in an inheritance relationship with the object's class.
For example, if I have a Zoo class, in the main method of Zoo, I might create a Tiger object. Tiger and Zoo will have no inheritance relationship.

[@joekeays]

great work!

[@BillBarnum]

Thanks, Mr. Keays!

[@lotax-jb3ot]

in 16:18, could you still call controlTemp with super(controlTemp())?

[@gash539]

good video

[@BillBarnum]

Thanks for the visit

[@savagebhuvan6279]

If you know all this will you be good to go for at least Mcq on inheritance on the AP exam.

[@BillBarnum]

I would recommend doing some practice questions to gauge your readiness. My favorite book is Barron's AP Computer Science A by Roselyn Teukolsky

[@savagebhuvan6279]

@@BillBarnum what about Princeton review? Is the 2023 version fine?

[@BillBarnum]

@@savagebhuvan6279
I haven't looked at the Princeton Review book recently, but there haven't been any meaningful changes in the curriculum since 2023.

[@itzwildguy]

@@savagebhuvan6279 Princeton is too weirdly worded; not straightforward

[@savagebhuvan6279]

@@itzwildguy I mean I'm doing the practice tests on Princeton and the explanations seem alright to me. If anything people r telling me Barron's explanations and notes are too vague.

[@xelzoid]

An hour before the exam

[@samuelatack5294]

Why the @ before Override?

[@BillBarnum]

Good question. It does two things:
1. It lets other programmers know that there is another version of the method in the superclass that they can call with super.
2. It causes Java to check to see if the method is really overriding another method and returns an error if it isn’t. It’s not unusual to make a small mistake and not realize that you aren't really overloading a method.

[@samuelatack5294]

@@BillBarnum ok thanks

[@Zappz2000x]

How does the super keyword work if there are multiple overridden methods?
For example:
Class #1 has a method, let's say "makeHappy()"
Class #2 extends Class #1 and also has a method "makeHappy()"
Class #3 extends Class #2 and ALSO has "makeHappy()"
If Class #4 extends Class #3 and calls "super.makeHappy()" would it return Class #3's or Class #1's? (and also can you call a specific class's method instead of just relying on the super word?)
If this is unclear, let me know and I'll try to reword it- thanks in advance!

[@BillBarnum]

If you called super.makeHappy() from Class4, it would call the version in Class3.

[@Clipzyy9401]

10 min til the test wish me luck lolololol

[@BillBarnum]

Good luck!

[@sreehanadigopula1904]

3 hours left for the test and i still don't know unit 9-10

[@Johnweely]

1 hours before exam I'm cooked 😢