AP Computer Science 1.1 Inheritance, Abstraction, and Polymorphism

problem states up arrows indicated inheritance relationship and we already

know that inheritance is just a big fancy word for

is a relationship No fast song is a song slow

song is a song too and we can go step

further and say power ballad is a slow song which

is a song Well we could extend this even further

by saying november rain is a power ballad november rain

than inherits any and all of the fields methods and

nested classes from power ballad which inherits from slow song

which inherits from song for exam song would contain members

that are relevant all songs and every subclass of song

things like are this name instruments song blank and so

on things that every song will have Well november rain

would be extremely specific like emotional axl rose vocal which

is something out every single half aside from simply knowing

their relationship between classes It's also important to know how

to properly declare and create a variable setting it all

up typically goes like this class variable named equals new

glass for supplies Yeah right left side of the equation

declares a variable to refer to An object song a

for example lets the compiler know that you're going to

use a to refer to data of the variety song

but that object doesn't actually yet exist On the other

side of the equation we get down and dirty and

actually a sign an object to that variable A new

power ballad for example would be created with song a

equals new power valid All right the question is asking

us which of these three option for declaring in creating

variables are correct starting with option one song a equals

new power balance and that's what we just did a

second ago and it works too and song be equals

New slow jam Yeah perfectly good way of creating a

slow jam Another good way would involve candles rose petals

and a saxophone solo But this is a little quicker

option One is good Option two is a little weird

It has as creating a slow song and power valid

and having them equal new song and slow song objects

but that's just not gonna fly the left side of

the equation declares variables name and its class and the

right side actually creates the object Option two is trying

to declare a variable of the type that's a subclass

of the actual object or creating that's like declaring that

you're going to be dracula for halloween But he actually

dress up some generic monster The option to option three

works like option one declaring variables and b to be

songs and then creates new fast song and slow song

objects So yeah three work with options One of three

working and to being wrong That makes the our answer