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Standard Data Structures Videos 18 videos

AP Computer Science 1.2 Standard Data Structures
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APCS: Standard Data Structures Drill 1, Problem 2. Which of the following methods are not appropriate for reuse in other programs?

AP Computer Science 3.2 Standard Data Structures
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AP Computer Science 3.2 Standard Data Structures. Which of the following methods successfully add an element to the array?

AP Computer Science 3.5 Standard Data Structures
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AP Computer Science: Standard Data Structures Drill 3, Problem 5. The resulting array from this code snippet has which of the following shapes?

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AP Computer Science 1.1 Standard Data Structures 194 Views


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Description:

AP Computer Science 1.1 Standard Data Structures. Which of the following method calls will result in an error?


Transcript

00:00

Thank you We sneak Then here's your shmoop toos your

00:05

brought to you with the explicit promise that will never

00:09

use cow puns will milk some utter ting for humor

00:14

Consider the following segment of code right there This thing

00:17

animal equals new animal best for cab equals new count

00:19

bessie for which of the following method calls will result

00:23

in an error and hear of potential answers Roman numerals

00:28

there Well this questions asking us about calling methods which

00:31

is pretty much a day to day thing in java

00:34

By now you've probably read a bit about classes relationships

00:36

and methods and could take a stab this question but

00:39

let's fully go over the nature of what we're dealing

00:41

with Imagine the following a super class vehicle which branches

00:45

down with a few subclass is called minivan motorcycle and

00:50

bicycle vehicle would contain members that could be useful tow

00:53

any type of vehicle number of wheels propulsion method whatever

00:57

you need Really the methods in the minivan class would

01:01

be specific to minivan objects Open sliding door full down

01:05

rear seats insist i am still cool it's on a

01:09

ce faras our question goes it's asking us which of

01:12

the attempts to call the method print mu will not

01:15

work well The question by design doesn't give us complete

01:19

information so we'll have to make a couple educated guesses

01:22

based on programming conventions for one will assume that animal

01:26

is a super class and that cow is a subclass

01:30

of it seems likely that animal and cow have an

01:33

inheritance or is a relationship since cow is a gn

01:37

animal and second will assume that print mu is a

01:39

method belonging to cow rather than the annals Not every

01:43

animal moves but most are all cows do so with

01:47

that in mind and with our snippet of code that

01:49

creates an animal object as a and a cow object

01:52

is b which of these attempts at calling print move

01:55

will not work We'll attempt one looks good b is

01:59

our cow object and this line calls the print moon

02:01

method appropriately attempt to looks a little weird What with

02:05

these parentheses all over the place we're casting b to

02:09

an animal and trying to call print move on it

02:12

Even though b is a cow the computer thinks it

02:14

is an animal because we've cast it so it'll give

02:18

us an error because print move doesn't exist in the

02:21

animal class In ten three uses object a an animal

02:25

without casting It is a cow so no dice there

02:29

One is a legal call but two and three or

02:31

not that means our answer is a hay If you

02:34

heard about the platypus that called customer service yeah he 00:02:37.935 --> [endTime] couldn't figure out why he got a bill

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