I'm a beginner when it comes to java and I'm lost on how to do my project
#Need Help with a project for class
fluid ibex
ember moatBOT
<@&987246399047479336> please have a look, thanks.
fluid ibex
I'm working on 9 files for this so this is what i have in them
public class Project2 {
public static void main(String args[]) {
}
}```public class ApplianceGUI {
}```Detected code, here are some useful tools:
fluid ibex
abstract public class Appliance {
protected int price;
private String SRN;
public Appliance (String SRN) {
this.SRN = SRN;
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
public int compareTo (Appliance x) {
return this.SRN.compareTo(x.SRN);
}
@Override
public boolean equals(Object other){
return other != null && getClass() == other.getClass() && SRN.equals(((Appliance) other).SRN); // check if two serial numbers equal each other
}
public char convert(){ // takes in a serial number and returns the first letter
if ((SRN.isEmpty())) return 'X';
return SRN.charAt(0);
}
public String getSRN() {
return SRN;
}
public void setSRN(String SRN) {
this.SRN = SRN;
}
}```Detected code, here are some useful tools:
fluid ibex
public class Refrigerator extends Appliance {
private int feet;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```Detected code, here are some useful tools:
fluid ibex
public class Microwave extends Appliance {
private int watts;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```Detected code, here are some useful tools:
fluid ibex
public class Dishwasher extends Appliance{
private boolean uci;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}
Detected code, here are some useful tools:
fluid ibex
public class ApplianceNode {
protected Appliance data;
protected ApplianceNode next;
public ApplianceNode(Appliance d) {
data = d;
next = null;
}
}```Detected code, here are some useful tools:
fluid ibex
public abstract class ApplianceList {
protected ApplianceNode first;
protected ApplianceNode last;
protected int length;
public ApplianceList() {
ApplianceNode dummy= new ApplianceNode(null);
first = dummy;
last = dummy;
length = 0;
}
public void append(Appliance a) {
ApplianceNode x = new ApplianceNode(a);
last.next = x;
last = x;
length++;
}
}```Detected code, here are some useful tools:
fluid ibex
public class SortedApplianceList extends ApplianceList {
public SortedApplianceList() {
super();
}
public void add(Appliance a) {
ApplianceNode p = first;
if (first == last) {
append(a);
}
while (p != null) {
if (p.next == null) {
append(a);
break;
}
if(p.next.data.compareTo(a)>= 0) {
ApplianceNode y = new ApplianceNode(a);
y.next = p.next;
p.next = y;
length++;
break;
}
p = p.next;
}
}
}````Detected code, here are some useful tools:
finite anchor
What's your specific question?
fluid ibex
I need help with it step by step because there is alot I don't understand
finite anchor
But what specifically are you stuck on?
fluid ibex
so I guess starting with the applainces
i'm stuck on the appliances rn
my refeg, dishwah, and micro
finite anchor
But what about of Appliances are you stuck on.
fluid ibex
all extend my applaince class
well for one the appliances
public class Refrigerator extends Appliance {
private int feet;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```i'm not sure how to write it
or how to use the tostring method here
i put price in my applance class
since it was supose to be in all the other 3 applainces
but as for the tostring method, i know we overrride it for the use of each appliance
but idk what to do with it
abstract public class Appliance {
protected int price;
private String SRN;
public Appliance (String SRN) {
this.SRN = SRN;
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
public int compareTo (Appliance x) {
return this.SRN.compareTo(x.SRN);
}
@Override
public boolean equals(Object other){
return other != null && getClass() == other.getClass() && SRN.equals(((Appliance) other).SRN); // check if two serial numbers equal each other
}
public char convert(){ // takes in a serial number and returns the first letter
if ((SRN.isEmpty())) return 'X';
return SRN.charAt(0);
}
public String getSRN() {
return SRN;
}
public void setSRN(String SRN) {
this.SRN = SRN;
}
}```So each appliance has a toString which should return something else.
finite anchor
And your assignment just states what's unique per appliance type.
fluid ibex
yea
i guess the first letter
i should probably mention this project is built off our first one
but in that one, we only had two files
like this was how it was written
ember moatBOT
I uploaded your attachments as Gist.
fluid ibex
and this was the appliance class
public class Appliance {
private String SRN;
public Appliance (String SRN) {
this.SRN = SRN;
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
public int compareTo (Appliance x) {
return this.SRN.compareTo(x.SRN);
}
@Override
public boolean equals(Object other){
return other != null && getClass() == other.getClass() && SRN.equals(((Appliance) other).SRN); // check if two serial numbers equal each other
}
public char convert(){ // takes in a serial number and returns the first letter
if ((SRN.isEmpty())) return 'X';
return SRN.charAt(0);
}
public String getSRN() {
return SRN;
}
public void setSRN(String SRN) {
this.SRN = SRN;
}
}```but with this project, we're using lists and nodes and inheriterence
maybe it doesn't help saying that but i thought i'd mention it
but yeah starting with the appliances in this project, since each has to return its own type of appliance back
finite anchor
Please do try to ask specific questions. Because I am honestly a bit puzzled what your specific issue is.
You keep stating appliances, without stating what the issue is.
fluid ibex
i'm not sure how to go about it
Alright, I need help with how to make it return an appliance for each type of appliance
what i mean is
public class Refrigerator extends Appliance {
private int feet;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```public class Microwave extends Appliance {
private int watts;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```public class Dishwasher extends Appliance{
private boolean uci;
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```these all extend my appliance class
i'm trying to figure out how to make it return that string of an applaince back
finite anchor
You just call the toString on appliance. It's generic, so the one of the actual type will be called.
fluid ibex
u say its generic, so that means my code doesn't know which appliance its talking about right?
maybe i need constuctors
but my appliance class has them
finite anchor
Appliance fridge = new Refridgerator();
When you then call toString on fridge the Refridgerator toString is used.
fluid ibex
public class Refrigerator extends Appliance {
private int feet;
public Refrigerator(int f){
feet = f;
}
@Override
public String toString() { // just returns the serial number
Appliance fridge = new Refrigerator();
return fridge;
}
}```it probably doesn't go in the method but i need to understand
so i wanna ask things
so since refeg extended to appliance
it means i can decalre refeg the same way i can declare an applaince?
finite anchor
Refridgerator should have a constructor which accepts feet.
Or call a setter.
As it stands you never get it.
Also a toString should not construct a new object.
It should just return a textual representation.
fluid ibex
alright but where would declaring the appliance go if no in the method or constuctor
finite anchor
Wherever you need it. Most likely where you start processing the file.
I recommend checking out:
fluid ibex
oh our main method
ember moatBOT
fluid ibex
Wherever you need it. Most likely where you start processing the file.
so this would be after reading the file i'm assuming
right i guess it woukdn't make sense to create the datatype of the refergrertor within it's class
fluid ibex
I recommend checking out:
I'll look at this, I thinking rn I need to make the arraylists in my main method for these three
Also apologies but I have to go rn but I'll be back in a couple of hours
finite anchor
No problem.
ember moatBOT
@fluid ibex
fluid ibex
Ok I'm back
fluid ibex
I think I'm confused
my subclasses wouldn't need to have the tostring method if it's already in the appliance class right?
abstract public class Appliance {
protected double price;
private String SRN;
public Appliance (String SRN) {
this.SRN = SRN;
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
public int compareTo (Appliance x) {
return this.SRN.compareTo(x.SRN);
}
@Override
public boolean equals(Object other){
return other != null && getClass() == other.getClass() && SRN.equals(((Appliance) other).SRN); // check if two serial numbers equal each other
}
public char convert(){ // takes in a serial number and returns the first letter
if ((SRN.isEmpty())) return 'X';
return SRN.charAt(0);
}
public String getSRN() {
return SRN;
}
public void setSRN(String SRN) {
this.SRN = SRN;
}
}```public class Refrigerator extends Appliance {
private int feet;
public Refrigerator(String SRN){
super(SRN);
}
@Override
public String toString(SRN) { // just returns the serial number
return SRN;
}
}```public class Microwave extends Appliance {
private int watts;
public Microwave(String SRN) {
super(SRN);
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```public class Dishwasher extends Appliance{
private boolean uci;
public Dishwasher(String SRN) {
super(SRN);
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
}```
unborn path
my subclasses wouldn't need to have the tostring method if it's already in the a...
they would not, correct
fluid ibex
so do i just make the tostrign method in appliance abstract
or well this is how i have rn
abstract public class Appliance {
private String SRN;
public Appliance (String SRN) {
this.SRN = SRN;
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
public int compareTo (Appliance x) {
return this.SRN.compareTo(x.SRN);
}
@Override
public boolean equals(Object other){
return other != null && getClass() == other.getClass() && SRN.equals(((Appliance) other).SRN); // check if two serial numbers equal each other
}
public char convert(){ // takes in a serial number and returns the first letter
if ((SRN.isEmpty())) return 'X';
return SRN.charAt(0);
}
public String getSRN() {
return SRN;
}
public void setSRN(String SRN) {
this.SRN = SRN;
}
}```public class Refrigerator extends Appliance {
private int feet;
private double price;
public Refrigerator(String SRN, double p,int f){
super(SRN);
feet = f;
price = p;
}
@Override
public String toString() { // just returns the serial number
return "Refrigerator - Serial Number: " + getSRN();
}
}```public class Microwave extends Appliance {
private int watts;
private double price;
public Microwave(String SRN, double p,int w) {
super(SRN);
watts=w;
price =p;
}
@Override
public String toString() {
return "Microwave - Serial Number: " + getSRN();
}
}```public class Dishwasher extends Appliance{
private boolean underCountInstall;
private double price;
public Dishwasher(String SRN,double p, boolean uci ) {
super(SRN);
price =p;
underCountInstall = uci;
}
@Override
public String toString() {
return "Dishwasher - Serial Number: " + getSRN();
}
}```also why does it tell me my getSRN is undefined when i extended to appliance
ember moatBOT
@fluid ibex
unborn path
@fluid ibex ping me in a few hours, i'll loop back. doing work
fluid ibex
<@541754479859728433> ping me in a few hours, i'll loop back. doing work
Alright got it
fluid ibex
hey sorry I was caught up with work for alot longer than i hoped
i wanted to say i got my code to work
but i still wanted to help to understand everything
I'll just post the code here but rn I just want explnations to what some parts of the code is doing
public class Project2 {
public static void main(String args[]) {
ApplianceGUI allAppliance = new ApplianceGUI();
allAppliance.readfile();
allAppliance.DisplayGUI();
}
}```
abstract public class Appliance {
private String SRN;
public Appliance (String SRN) {
this.SRN = SRN;
}
@Override
public String toString() { // just returns the serial number
return SRN;
}
public int compareTo (Appliance x) {
return this.SRN.compareTo(x.SRN);
}
@Override
public boolean equals(Object other){
return other != null && getClass() == other.getClass() && SRN.equals(((Appliance) other).SRN); // check if two serial numbers equal each other
}
public char convert(){ // takes in a serial number and returns the first letter
if ((SRN.isEmpty())) return 'X';
return SRN.charAt(0);
}
public String getSRN() {
return SRN;
}
public void setSRN(String SRN) {
this.SRN = SRN;
}
}```public class Refrigerator extends Appliance {
private int feet;
private double price;
public Refrigerator(String SRN, double p,int f){
super(SRN);
feet = f;
price = p;
}
@Override
public String toString() { // just returns the serial number
return "Refrigerator - Serial Number: " + getSRN();
}
}```public class Microwave extends Appliance {
private int watts;
private double price;
public Microwave(String SRN, double p,int w) {
super(SRN);
watts=w;
price =p;
}
@Override
public String toString() {
return "Microwave - Serial Number: " + getSRN();
}
}```public class Dishwasher extends Appliance{
private boolean underCountInstall;
private double price;
public Dishwasher(String SRN,double p, boolean uci ) {
super(SRN);
price =p;
underCountInstall = uci;
}
@Override
public String toString() {
return "Dishwasher - Serial Number: " + getSRN();
}
}```public class ApplianceNode {
protected Appliance data;
protected ApplianceNode next;
public ApplianceNode(Appliance d) {
data = d;
next = null;
}
}```public abstract class ApplianceList {
protected ApplianceNode first;
protected ApplianceNode last;
protected int length;
public ApplianceList() {
ApplianceNode dummy= new ApplianceNode(null);
first = dummy;
last = dummy;
length = 0;
}
public void append(Appliance a) {
ApplianceNode x = new ApplianceNode(a);
last.next = x;
last = x;
length++;
}
}```public class SortedApplianceList extends ApplianceList {
public SortedApplianceList() {
super();
}
public void add(Appliance a) {
ApplianceNode p = first;
if (first == last) {
append(a);
}
while (p != null) {
if (p.next == null) {
append(a);
break;
}
if(p.next.data.compareTo(a)>= 0) {
ApplianceNode y = new ApplianceNode(a);
y.next = p.next;
p.next = y;
length++;
break;
}
p = p.next;
}
}
}```this was the file we had to read from
R45839RHJ783,2195,22
R389502JNM32,972,16
R2847786SFLK,1599,20
M1189SSK9023,295,50
M8579UKH9RI3,49,10
M7389FIE9283,99,25
D78WJH7662DJ,589,Y
D44NDMDOE758,399,N
D82974IOUFDB,1280,Y
R37859KDIUW7,1285,17
R378OEJF7834,1366,15
M349FJKEI374,299,30
D234NDJF8372,458,Y
M8934KFD8394,129,12
M4589EFKEJ34,159,14
R349FJKE9383,875,12
D73I9ER83742,952,Y
D28994KFH893,457,N
R38DH39462KE,2399,25
R34RE837563I,456,10
and finally this is what it prints
now for my questions
fluid ibex
```java
public class SortedApplianceList extends ApplianceList {
public Sort...
for my sortedApplianceList, could u explain what's fully going on in the add method with the conditions that lead to appending, the one where we check if the node is null and the compareTo for clarification
fluid ibex
for this code,
public void FillGUI() {
Container myContentPane = getContentPane();
TextArea refeg = new TextArea();
TextArea dishWash = new TextArea();
TextArea micro = new TextArea();
setLayout(new GridLayout(1,3));
ApplianceNode curr = rList.first.next;
while(curr !=null) {
refeg.append(curr.data.toString() + "\n");
curr=curr.next;
}
ApplianceNode curr2 = dList.first.next;
while(curr2 !=null) {
dishWash.append(curr2.data.toString()+ "\n");
curr2=curr2.next;
}
ApplianceNode curr3 = mList.first.next;
while(curr3 !=null) {
micro.append(curr3.data.toString() + "\n");
curr3=curr3.next;
}
refeg.setEditable(false);
dishWash.setEditable(false);
micro.setEditable(false);
myContentPane.add(refeg);
myContentPane.add(dishWash);
myContentPane.add(micro);
}```
could you explain what exactly ```ApplianceNode curr = rList.first.next;``` is saying?waking up
unborn path
for my sortedApplianceList, could u explain what's fully going on in the add met...
public class SortedApplianceList extends ApplianceList {
public SortedApplianceList() {
super();
}
public void add(Appliance a) {
ApplianceNode p = first;
if (first == last) {
append(a);
}
while (p != null) {
if (p.next == null) {
append(a);
break;
}
if(p.next.data.compareTo(a)>= 0) {
ApplianceNode y = new ApplianceNode(a);
y.next = p.next;
p.next = y;
length++;
break;
}
p = p.next;
}
}
}
okay so I think that if (first == last) is a ghetto "is empty" check
then the next part is an insertion sort
just puts the element in the right place in the list
but didn't you write this code?
what exactly am i explaining?
fluid ibex
but didn't you write this code?
No I did but I also had help so there were some things that weren’t fully clear
fluid ibex
what exactly am i explaining?
The conditions as to when we append
unborn path
No I did but I also had help so there were some things that weren’t fully clear
was that help AI
fluid ibex
I just wanted an explanation on what they did to make sure I got it fully
fluid ibex
was that help AI
No a tutor
fluid ibex
I don’t use ai to do code
unborn path
The conditions as to when we append
well basically it always appends
fluid ibex
But to explain things to me sometimes
unborn path
so long as the item isn't already in the list
while (p != null) {
if (p.next == null) {
append(a);
break;
}
if(p.next.data.compareTo(a)>= 0) {
ApplianceNode y = new ApplianceNode(a);
y.next = p.next;
p.next = y;
length++;
break;
}
p = p.next;
}
But it would defeat the purpose of me learning if I did that 😭
unborn path
correct, good job
but okay
the way this works is - if we reach the end of this linked list we append
we only reach the end if we didn't find a place to put it before the end
so going left to right
lets say we have this list
4 -> 7 -> 9 -> 22
and we want to insert 8
so we start here
V
4 -> 7 -> 9 -> 22
if(p.next.data.compareTo(a)>= 0) {
so the next is 7
is 7 greater than or equal to 8? no
so next
V
4 -> 7 -> 9 -> 22
the next one is 9
so is 9 greater than or equal to 8? yes
so this is where we splict in 8
4 -> 7 -> 8 -> 9 -> 22
now lets insert 9999
it will make it all the way to the end
V
4 -> 7 -> 8 -> 9 -> 22 -> null
and this is where it hits this branch
if (p.next == null) {
append(a);
break;
}
and thats when we append
when there is no place before the end to add the thing
fluid ibex
for this code,
```java
public void FillGUI() {
Container myContentPane =...
Alright so for this one, could u explain ApplianceNode curr=rList.first.next;
Like what exactly it’s doing
finite anchor
What do you think it does?
fluid ibex
Going through the linked list
But there is a lot of dots
Actually it’s the while u would use to go through each of list until the end
finite anchor
Do you know the difference between: foo.bla and foo.bla()?
fluid ibex
But I know once u do, u add in the info u collected from reading onto that specific appliance list
If foo.bla is a built in function then no
But if it’s about the parenthesis
finite anchor
What is foo?
fluid ibex
No idea
finite anchor
Ok, what is your rList?
fluid ibex
Haven’t ever heard of foo
finite anchor
Don't think too far.
fluid ibex
Ok, what is your rList?
It’s meant to be a sorted list of refrigerators
Yes that’s what’s it’s declared as
fluid ibex
It’s a linked list
finite anchor
That wasn't the question.
fluid ibex
rList is the variable that stores a linked list data type I made
finite anchor
That's not the question.
finite anchor
My question is literally:
foo; <= variable or method
bar(); <= variable or method
Because the reason you don't get what's going on is seemingly you not noticing/knowing/recognizing what they respectively are.
fluid ibex
Oh I see
Second one is method
Cause parenthesis
First one would be a vairbke
Every method has parenthesis
That was the question then
finite anchor
So what would rList.first indicate?
fluid ibex
Its a pointer maybe
finite anchor
What?
finite anchor
Yes, and do you know how to call the methods of a variable, or access it's accessible variables?
finite anchor
Ok. so first has no parenthesis, so what is it? Variable or method?
fluid ibex
I only think it’s a method cause of the dot
But it doesn’t have parenthesis
So it could just be a vairbke
finite anchor
No, a dot just indicates you're acting upon what's to the left of the dot.
fluid ibex
Okay so it would be good to ask
What does rList.first indicate
Cause I’m seeing that I don’t know
finite anchor
I am trying to figure out where/why you're stuck.
You know rList is a variable, and you know its type.
You know . indicates we're using something of the variable/class to the left of it.
fluid ibex
I think I was confused with nodes
Cause I recently learned it
But first is the first node
finite anchor
In this case the specific type doesn't even matter.
fluid ibex
Does that mean it’s the first thing in the linked list
finite anchor
It's just .first vs .first(). Both could indicate a note. In the former case as a variable, the second case a method.
Well second since they also use .next.
fluid ibex
oh alright
okay so rList.first
means it's looking at the first node?
and then .next
finite anchor
Yes.
fluid ibex
the one after?
finite anchor
It gets the next element of the first node.
Or rather, it gets the next element of the node it's called upon. Which in this case is the first node.
fluid ibex
so the first calls the next node then
u know what
lemme draw this out
i need visual represenation
Ok so currently that’s what just that line is doing right
fluid ibex
Okay
This is what I think is happening
So there is a node called curr and I’m saying that inside the list, it’ll be pointed to the first node which points the next node
And the while loop is gonna go through the entire list until it’s very last which is null
And throughout that process, each time, it’s gonna print the current serial number in the list in the textarea
And once it’s printed that current one, the next current node will be the node after that in the rList
That’s what I think is happening
I’m sure something is wrong with that but that’s what I think is going on
ember moatBOT
@fluid ibex