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AP Computer Science 1.2 Inheritance, Abstraction, and Polymorphism 369 Views
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Description:
APCS: Inheritance, Abstraction, and Polymorphism Drill 1, Problem 2. Which of the following is the correct way to begin writing your class?
Transcript
- 00:00
Sorry And here's your shmoop to use your brought to
- 00:05
you by object oriented programming It's got class that's really
- 00:10
funny the computer science majors around us or just rolling
- 00:13
on the floor right All right you would like to
- 00:15
define a subclass called bicycle as part of your ongoing
Full Transcript
- 00:19
efforts to reduce your carbon footprint Which of the following
- 00:23
is a correct way to begin writing your class carbon
- 00:27
footprint like tires All right And here the potential answers
- 00:32
public clan All right well the key to answering this
- 00:37
question is knowing the syntax of defining a subclass in
- 00:40
java But what is a sub class submarine class Well
- 00:44
it's a lot like a normal class except a subclass
- 00:47
also inherits things from the super class it's extending from
- 00:51
so once we get set up and we're messing around
- 00:53
with our new bicycle class we'll be able to use
- 00:55
the access or methods of vehicle that we've already written
- 00:59
Got it all right Well this idea is known as
- 01:01
inheritance in object oriented programming and it doesn't involve trying
- 01:05
to make your distant ninety eight year old relatives think
- 01:08
you're interesting Anyhow this is a question of syntax and
- 01:12
that's In texas public class new subclass extends class way
- 01:18
know for a fact that bicycle is intended to be
- 01:20
a subclass of vehicle It hangs down like fruit on
- 01:24
a tree so he is certainly out He creates a
- 01:26
class called vehicle that extends from bicycle and it's the
- 01:29
wrong way around Option a is also an option a
- 01:32
uses new to declare the subclass bicycle exist but the
- 01:36
question is asking us to define it similar words but
- 01:39
two very different things A declaration simply says something exists
- 01:43
but doesn't describe what the class or function actually does
- 01:47
The question was asking us to define the class Instead
- 01:51
option b and c use the word super rather than
- 01:54
extends which isn't proper syntax whatsoever So that just leaves
- 01:58
us with d which has both the correct syntax and 00:02:00.796 --> [endTime] the classes in their proper order They were walking
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