Java assignment don't know what is the mistake - java

the question is :
A fruit shop sells several types of fruits each day. Write a program that reads from user several lines of input.Each line includes a fruit's name,price per kilogram (as an integer), number of kilograms sold (as an integer).
the program should calculate and print the earned money of all fruits sold and fruit that achieved largest profit.
hint: -you could assume that user will insert valid data -user could stop the program via entering the word "stop" as a fruit's name.
Sample input and out put:
in each line, insert a fruit's name, price per kilogram, number of kilograms sold. To halt the program,insert "stop" as a fruit's name
banana 2 11
mango 3 8
peach 4 5
stop
the earned money of all fruits sold: 66
fruit that achieved the largest profit: mango
what i wrote now:
public static void main(String[] args) {
// TODO code application logic here
Scanner input = new Scanner (System.in);
String fruitname= " ";
String maxfruit = " ";
int price = 0,number=0;
int sum=0;
int max=0;
System.out.print("Fruit name, " + "price in killogram, number of killogram sold: ");
while (!fruitname.equals("stop"))
{
fruitname = input.next();
price = input.nextInt();
number = input.nextInt();
}
if (fruitname.equals("stop"))
{
sum = sum+(price*number);
}
if (max<(price*number))
{
max = price*number;
maxfruit = fruitname;
}
System.out.println("the earned money of all fruits is " + sum);
System.out.println("fruit that achieved the largest profit is "+ maxfruit);
}
}
the program is not reading what i submit to it, don't know why and not giving me the sum and the max fruit.. what is the problem of what i wrote?

As you can see your reads happen in the while loop:
while (!fruitname.equals("stop"))
{
fruitname = input.next();
price = input.nextInt();
number = input.nextInt();
}
Every time it loops - it overrides the values. Finally when you read stop and exit the loop - your fruitname is stop. So you need to fix your logic on how you would want to read in the input

Working variant:
public class FruitTest {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Fruit name, " + "price in killogram, number of killogram sold: ");
String text = input.nextLine();
String[] words = text.split(" ");
List<Fruit> fruits = parseInput(words);
int sum = getSum(fruits);
String popular = getPopularFruitName(fruits);
System.out.println("Got fruits: " + fruits.toString());
System.out.println("the earned money of all fruits is " + sum);
System.out.println("fruit that achieved the largest profit is " + popular);
}
private static String getPopularFruitName(List<Fruit> fruits) {
int max = 0;
String name = null;
for (Fruit fruit : fruits) {
int checkVal = fruit.getPrice() * fruit.getAmount();
if(checkVal > max) {
max = checkVal;
name = fruit.getName();
}
}
return name;
}
private static int getSum(List<Fruit> fruits) {
int result = 0;
for (Fruit fruit : fruits) {
result += fruit.getPrice() * fruit.getAmount();
}
return result;
}
private static List<Fruit> parseInput(String[] words) {
List<Fruit> result = new ArrayList<Fruit>();
int element = 1;
final int name = 1;
final int price = 2;
final int amount = 3;
Fruit fruit = null;
for (String word : words) {
if (word.equals("stop") || word.isEmpty()) {
break;
}
if(element > amount)
element = name;
switch (element) {
case name:
fruit = new Fruit(word);
result.add(fruit);
break;
case price:
if (fruit != null) {
fruit.setPrice(Integer.valueOf(word));
}
break;
case amount:
if(fruit != null) {
fruit.setAmount(Integer.valueOf(word));
}
break;
}
element++;
}
return result;
}
static class Fruit {
String name;
int price = 0;
int amount = 0;
Fruit(String name) {
this.name = name;
}
String getName() {
return name;
}
int getPrice() {
return price;
}
void setPrice(int price) {
this.price = price;
}
int getAmount() {
return amount;
}
void setAmount(int amount) {
this.amount = amount;
}
#Override
public String toString() {
return name + ". $" + price +
", amount=" + amount;
}
}
}
Comments to code - it's proper way to parse all the inputted string and parse it to an object that stores all the data - name, price and amount. Store all parsed objects into array or a list and then calculate max and popular fruit while looping your parsed fruit array

I found some mistake. The most important was in the while condition. Check this out.
public static void main(String[] args) {
// TODO code application logic here
Scanner input = new Scanner (System.in);
String fruitname = null;
String maxfruit = null;
int fruitSum = 0;
int totalSum = 0;
int max = 0;
System.out.print("Fruit name, " + "price in killogram, number of killogram sold: ");
while(!(fruitname = input.next()).equals("stop")){
fruitSum = input.nextInt() * input.nextInt();
totalSum += fruitSum;
if(fruitSum > max){
maxfruit = fruitname;
max = fruitSum;
}
}
System.out.println("the earned money of all fruits is " + totalSum);
System.out.println("fruit that achieved the largest profit is "+ maxfruit);
}
}

Oh it is reading it.
the problem is that it doesn't do what you want it to do.
the problems with the code I can see are this:
you are not storing the fruits quantities or prices anywhere, you need to store the values
in an array or something (maxFruit,MaxValue) to compare them later.
when you are reading the fruit values and a "stop" string is input the next step in your code is to wait for the price so it won't get out of the loop even if you input "stop", you need to restructure your scanner loop.
And if it is a beginner class it may be ok, but the code you are writing is not object oriented don't write the logic in the main.
You may want to learn to debug it is a very useful tool when you are learning to code, if you run this program in debug mode , you could see that the values are getting input and everything that is happening, Netbeans and Eclipse have very good debuggers and it would be worth to expend half an hour learning the basics of debugging It certainly helped me a lot when I was starting.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class FruitSells {
public static void main(String... args) {
BufferedReader bufer = new BufferedReader(new InputStreamReader(System.in));
try {
String str;
String[] inarr;
int sumMoney = 0;
do {
str = (String) bufer.readLine();
inarr = str.split(" ");
for(int i = 1; i < inarr.length; i += 3) {
sumMoney += Integer.parseInt(inarr[i]) * Integer.parseInt(inarr[i + 1]);
}
System.out.println(sumMoney);
sumMoney = 0;
} while (!str.equals("stop"));
} catch(IOException ex) {
System.out.println("Problems with bufer.readLine()");
}
}
}
something like this you can modernize it.sorry for eng i can not speak))and write correctly of course))

Related

I have to do this task (online shop) using "switch" statements. I got stuck

"Write a Java program to simulate an online store. The program should begin
by displaying a list of products and their prices. There should be a minimum of 4
products offered.
My code is below, it works without the strings but I need to have names for the cakes(display names and prices)
import java.util.Scanner;
public class Main
{
public static void main(String[] args) {
Scanner input= new Scanner(System.in)
int cakeNo = 0;
double cake1;
double cake2;
double cake3;
double cake4;
double cake5;
int quantity;
double totalSales = 0;
while(cakeNo !=0 )
System.out.println("Enter cake number 1-5");
cakeNo=input.nextInt();
System.out.println("Enter quantity");
quantity = input.nextInt();
switch (cakeNo){
case 1: cake1 = 3.70;
totalSales+=(3.70*quantity);
break;
case 2: cake2 = 4.20;
totalSales+=(4.20*quantity);
break;
case 3: cake3 = 4.50;
totalSales+=(4.50*quantity);
break;
case 4: cake4 = 5.00;
totalSales+=(5.00*quantity);
break;
case 5: cake5 = 5.50;
totalSales+=(5.50*quantity);
break;
}
System.out.println(totalSales);
}
}
Thank you so much for reading! Please help if you have an idea.
Well there are a few things wrong in your code that you should take care first.
First: The first 5 string are wrongly defined. It should be like this String cake1 = "Angel cake" and so on.
Second: The strings and doubles have the same names you cannot do that. You need to have something like String cake1Name = "Name" and double cake1Price = price this way you have two distinct properties for everycake.
Third: Right now the code doesn't even enters the while loop. Since cakeNo starts with 0 and the condition in your while loop is cakeNo != 0 right on before the first loop this condition will be tested and it will be false meaning that the loop code won't be executed and will jump to the end of the program.
After this fixes there is still a little problem. After you get the input from the user if said input is 0 meaning that he wants to leave the program will still ask him for a quantity. You need to add/change something that breaks the loop when this conditions is true. I don't want to give you code but I hope this answer can help you good luck :)
This is what I would do:
public class Main {
LinkedList<Product> cart = new LinkedList<Product> ();
Scanner scanner = new Scanner(System.in);
double tax = 7.5;
boolean done = false;
public Main() {
cart.add(new Product("Cake 1", 3.70));
cart.add(new Product("Cake 2", 4.20));
cart.add(new Product("Cake 3", 4.50));
cart.add(new Product("Cake 4", 5.00));
cart.add(new Product("Cake 5", 5.50));
}
public void displayCart() {
for (int i = 0; i < cart.size(); i++) {
switch (cart.get(i).quantitySelected){
case 0:
System.out.println(i + ": " + cart.get(i).name + " none selected");
break;
default:
System.out.println(i + ": " + cart.get(i).name + " selected: " + cart.get(i).quantitySelected);
break;
}
}
}
public void addToCart(int product, int amount) {
cart.get(product).select(amount);
}
public void getSelection() {
int productSelected;
System.out.println("enter a product value or FINNISHED to end: ");
try {
productSelected = scanner.nextInt();
} catch (InputMismatchException e) {
done = true;
return;
}
System.out.println("enter amount to select: ");
int amount = scanner.nextInt();
cart.get(productSelected).select(amount);
}
public double getSubtotal() {
double cost = 0.00;
for (Product product : cart) {
cost += product.cost * product.quantitySelected;
}
return cost;
}
public double getTotal() {
return getSubtotal() + getSubtotal()*tax;
}
public void finnishPurchase() {
System.out.println("---------------------");
System.out.println("subtotal: " + getSubtotal());
System.out.println("tax: " + tax);
System.out.println("total: " + getTotal());
}
public static void main(String[] args) {
Main store = new Main();
while (!store.done) {
store.displayCart();
store.getSelection();
}
store.finnishPurchase();
}
}
public class Product {
String name;
double cost;
int quantitySelected = 0;
public Product(String name, double cost) {
this.name = name;
this.cost = cost;
}
public void select(int quantity) {
quantitySelected = quantity;
}
}

How do I populate a String array using a for loop [duplicate]

This question already has answers here:
Scanner is skipping nextLine() after using next() or nextFoo()?
(24 answers)
Closed 4 years ago.
Please bear in mind that I am a beginner.
I have written the following code to try to populate a String array. It runs but will not print out the contents of the String array positions. (The same thing seems to work no problem for the double Array!)I do not understand why this is. If anyone could help me solve this problem I would be extremely grateful. See below for the code of the Main Class and a class called Fruit which contains the methods I am using.
`enter code here`Main class:
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Fruit fruit = new Fruit();
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the number of items in your shopping list:");
int listSize = scanner.nextInt();
String[] sl = new String[listSize];
double[] price = new double[listSize];
//Loop asking user to enter items and prices
for(int i = 0; i <= listSize - 1; i++)
{
System.out.println("Enter item " + (i+1) + ":");
fruit.setName(scanner.nextLine());
sl[i] = fruit.getName();
scanner.next();
System.out.print("Price of " + sl[i] + ":");
fruit.setPrice(scanner.nextDouble());
price[i] = fruit.getPrice();
}
//Loop printing items and their prices
for(int i = 0; i <= listSize - 1; i++)
{
System.out.println(sl[i] + " cost " + price[i]);
}
//Order the array in ascending order so as to be able to easily
identify the most and least expensive
Arrays.sort(price);
//Print out the most expensive and cheapest prices
System.out.println("The most expensive item costs: " +
price[price.length-1]);
System.out.println("The least expensive item costs: " + price[0]);
}
}
Fruit Class:
public class Fruit {
private String name;
private double price;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}
The problem is that the Scanner.readInt() and Scanner.readDouble() methods do not read the newline character after you press enter. However, the readLine() method reads the input that is skipped, so it reads the newline character. To fix the problem, you need to call scanner.readLine() after you call scanner.readInt() and scanner.readDouble() to get rid of the newline. Please see the code below.
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Fruit fruit = new Fruit();
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the number of items in your shopping list:");
int listSize = scanner.nextInt();
scanner.nextLine(); //calling nextLine() to get rid of the newline character
String[] sl = new String[listSize];
double[] price = new double[listSize];
//Loop asking user to enter items and prices
for(int i = 0; i <= listSize - 1; i++)
{
System.out.println("Enter item " + (i+1) + ":");
fruit.setName(scanner.nextLine());
sl[i] = fruit.getName();
System.out.print("Price of " + sl[i] + ":");
fruit.setPrice(scanner.nextDouble());
scanner.nextLine(); //calling nextLine() to get rid of the newline character
price[i] = fruit.getPrice();
}
//Loop printing items and their prices
for(int i = 0; i <= listSize - 1; i++)
{
System.out.println(sl[i] + " cost " + price[i]);
}
//Order the array in ascending order so as to be able to easily
Arrays.sort(price);
//Print out the most expensive and cheapest prices
System.out.println("The most expensive item costs: " + price[price.length-1]);
System.out.println("The least expensive item costs: " + price[0]);
}
}
class Fruit
{
private String name;
private double price;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
}
I have compiled and run this code, and here is the output it produces:
Enter the number of items in your shopping list:2
Enter item 1:
apple
Price of apple:1.25
Enter item 2:
bread
Price of bread:3.45
apple cost 1.25
bread cost 3.45
The most expensive item costs: 3.45
The least expensive item costs: 1.25
Hope this helps!!

scanner nextLine() skip and failed read

Not actually sure what's wrong, just that at line 81 my scan object is skipped and then the program continues with no clear attempt to read anything, thoughts on what's wrong? btw working in eclipse
import java.util.*;
public class Hospital
{
//--- Instance Variables
private Patient patient;
private Scanner scan;
private double totalPrivateRoomCharges;
private double totalSemiPrivateRoomCharges;
private double totalWardRoomCharges;
private double totalTelephoneCharges;
private double totalTelevisionCharges;
private double totalReceipts;
//--- Constructors
public Hospital()
{
scan = new Scanner(System.in);
totalPrivateRoomCharges = 0;
totalSemiPrivateRoomCharges = 0;
totalWardRoomCharges = 0;
totalTelephoneCharges = 0;
totalTelevisionCharges = 0;
totalReceipts = 0;
mainMenu();
}
//--- Methods
public void mainMenu()
{
int ans = 0;
do
{
System.out.println(" Community Hospital");
System.out.println();
System.out.println(" Main Menu");
System.out.println();
System.out.println("1) Enter Patient Billing Information");
System.out.println("2) Print Daily Summary Report");
System.out.println("3) Exit");
System.out.println();
System.out.print("Selection: ");
ans = scan.nextInt();
System.out.println();
if(ans == 1)
{
patientBillingInfo();
}
if(ans == 2)
{
printSummaryReport();
}
}
while(ans != 3);
}
// precondition: none
// postcondition: displays a menu that allows the user to enter a patient's
// billing info which includes the patient's name, the number of days the
// patient stayed in the hospital, and the type of room
// (private, semi-private, ward).
// Once the patient info is retrieved a patient object is created and a
// billing report is generated that includes the patient's name, length
// of stay, and the charges incurred including the bill total.
// The totals that are used to print the hospitals daily summary report
// are updated.
public void patientBillingInfo()
{
String name = "";
int days = 0;
String room = "";
System.out.println(" Community Hospital");
System.out.println();
System.out.println(" Patient Billing Query");
System.out.println();
System.out.println("Enter Patient Name: ");
here the scan object seems to be completely skipped and dose not read at all just moves to the next line and continues.
name = scan.nextLine(); //getting skiped
System.out.println("Enter number of days in Hospital: ");
days = scan.nextInt();
System.out.println("Enter Room type(P, S, W): ");
room = scan.next();
System.out.println();
System.out.println();
if(!((room.equalsIgnoreCase("P")) || (room.equalsIgnoreCase("S")) || (room.equalsIgnoreCase("W"))))
{
System.out.println("Incorect room information");
System.out.println("Please enter P, S, or W for room selection");
System.out.println();
patientBillingInfo();
}
else
{
if(room.equalsIgnoreCase("P"))
totalPrivateRoomCharges += 1*days;
if(room.equalsIgnoreCase("S"))
totalSemiPrivateRoomCharges += 1*days;
if(room.equalsIgnoreCase("W"))
totalWardRoomCharges += 1*days;
totalTelephoneCharges += 1*days;
totalTelevisionCharges += 1*days;
patient = new Patient(name, days,room);
}
System.out.println(" Community Hospital");
System.out.println();
System.out.println(" Patient Billing Statement");
System.out.println();
System.out.println("Patient's name: " + patient.getName());
System.out.println("Number of days in Hospital: " + patient.getDays());
System.out.println();
System.out.println("Room charge $ " + patient.getRoomCharge());
System.out.println("Telephone charge $ " + patient.getTelephoneCharge());
System.out.println("Television charge $ " + patient.getTelevisionCharge());
System.out.println();
System.out.println("Total charge $ " +patient.getTotalCharge());
System.out.println();
System.out.println();
mainMenu();
}
// precondition: none
// postcondition: a summary report is printed that includes the daily total
// room charges for each type of room, the daily total telephone charges,
// and the daily total television charges. The report also includes the
// total receipts for the day.
public void printSummaryReport()
{
double tPRC = 225.0*totalPrivateRoomCharges;
double tSPRC = 165.0*totalSemiPrivateRoomCharges;
double tWRC = 95.0*totalWardRoomCharges;
double tTpC = 1.75*totalTelephoneCharges;
double tTvC = 3.50*totalTelevisionCharges;
double tR = tPRC+tSPRC+tWRC+tTpC+tTvC;
System.out.println(" Community Hospital");
System.out.println();
System.out.println(" Daily Billing Summary");
System.out.println();
System.out.println("Room Charges");
System.out.println(" Private: $" + tPRC);
System.out.println(" Semi-Private: $" + tSPRC);
System.out.println(" Ward: $" + tWRC);
System.out.println("Telephone Charges: $" + tTpC);
System.out.println("Telvision Charges: $" + tTvC);
System.out.println();
System.out.println("Total Receipts: $" + tR);
System.out.println();
}
}
edit: so it just occurred to me that maybe just maybe the rest of the code that this goes with might be useful dunno why I didn't think about this sooner but here's the rest
the class that actually runs
public class Administrator
{
public static void main(String[] args)
{
Hospital hospital = new Hospital();
}
}
and the class that works the patient info
public class Patient
{
//--- Constants
public final double PRIVATE = 225.00;
public final double SEMI = 165.00;
public final double WARD = 95.00;
public final double TELEPHONE = 1.75;
public final double TELEVISION = 3.50;
//--- Instance Variables
private String name;
private String roomType;
private int days;
//--- Constructors
public Patient(String n, int d, String rT)
{
name = n;
days = d;
roomType = rT;
}
//--- Methods
// precondition: none
// postcondition: returns the patient name
public String getName()
{
return name;
}
// precondition: none
// postcondition: returns the length of stay in days
public int getDays()
{
return days;
}
// precondition: none
// postcondition: returns the room type ("P", "S", "W")
public String getRoomType()
{
return roomType;
}
// precondition: none
// postcondition: returns the room charge which is dependant upon
// the room type and the length of stay.
public double getRoomCharge()
{
double charge = 0;
if(getRoomType().equalsIgnoreCase("P"))
charge = 225.00*getDays();
if(getRoomType().equalsIgnoreCase("S"))
charge = 165.00*getDays();
if(getRoomType().equalsIgnoreCase("W"))
charge = 95.00*getDays();
return charge;
}
// precondition: none
// postcondition: returns the telephone charge which is dependant upon
// the length of stay
public double getTelephoneCharge()
{
double charge = 1.75*getDays();
return charge;
}
// precondition: none
// postcondition: returns the television charge which is dependant upon
// the length of stay
public double getTelevisionCharge()
{
double charge = 3.50*getDays();
return charge;
}
// precondition: none
// postcondition: returns the total charge which is the sum
// of the room charge, telephone charge, and television charge.
public double getTotalCharge()
{
double charge = getRoomCharge()*getTelephoneCharge()+getTelevisionCharge();
return charge;
}
}
really don't know why it didn't occur to me sooner to do this but whatever live and lern right
You could simply scan a line and then parse it as the integer for Integer values.
so for reading integers instead of
val=scan.nextInt()
you could use
String strVal = scan.nextLine();
try {
val = Integer.parseInt(strVal);
} catch (NumberFormatException e) {
//maybe try again, or break the code ... or proceed as you wish.
}
this is because the nextInt() does not take the "Enter" key into account, and when you press enter after the nextInt() the int is read into the variable expecting nextInt() and the "Return" Key is accepted by the nextLine() which results in an empty line being read into the variable.
In public void mainMenu() you need to add scan.nextLine(); after ans = scan.nextInt(); in order to clear the rest of the input buffer.
ans = scan.nextInt();
scan.nextLine(); // <----- Add this line here

Calling methods of an object that is already stored in an ArrayList

Everything works so far in my program but I'm having trouble with this section of my code:
else if(input.equals("2")) {
System.out.println("Enter the stock symbol:");
symbol2 = in.next();
System.out.println("Enter the number of shares you wish to sell:");
sellshares = in.nextInt();
String tempsymbol = "";
for(int i=0; i<array1.size(); i++) {
tempsymbol = (array1.get(i)).getSymbol();
if(symbol2.equals(tempsymbol)) {
System.out.println("The dollar cost averaged price per share (LIFO): " + (array1.get(i)).averageCost(sellshares));
System.out.println("The dollar cost averaged price per share (FIFO): " + (array2.get(i)).averageCost(sellshares));
}
}
}
It'll go through the loop but tempsymbol will always = "". Why doesn't array1 return anything?
Here's all my code. Apologies ahead of time if any parts are redundant or messy.
import java.util.*;
public class Whoop {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String input = "";
String symbol = "";
String name = "";
int shares = 0;
double price = 0;
String symbol2 = "";
int sellshares = 0;
int rolling = 0;
stack theStack = null;
queue theQ = null;
String loopcheck = "1";
ArrayList<stack> array1 = new ArrayList<stack>();
ArrayList<queue> array2 = new ArrayList<queue>();
while(loopcheck.equals("1")) {
System.out.println("Press 1 to enter a new stock or press 2 to find the LIFO and FIFO dollar cost average for the number of shares sold");
input = in.next();
if(input.equals("1")) {
System.out.println("Enter the stock symbol:");
symbol = in.nextLine();
in.nextLine();
System.out.println("Enter the stock name:");
name = in.nextLine();
System.out.println("Enter the number of shares bought:");
shares = in.nextInt();
System.out.println("Enter the price per share when purchased");
price = in.nextDouble();
theStack = new stack(symbol,name,shares,price);
theQ = new queue(symbol,name,shares,price);
System.out.println("Press 1 to continue entering new shares or press 2 to finish input for " + theStack.getName());
rolling = in.nextInt();
while(rolling == 1) {
System.out.println("Enter the number of shares bought:");
shares = in.nextInt();
System.out.println("Enter the price per share when purchased");
price = in.nextDouble();
theStack.bigPush(shares, price);
theQ.bigAdd(shares, price);
System.out.println("Press 1 to continue entering new shares or press 2 to finish input for " + theStack.getName());
rolling = in.nextInt();
}
array1.add(theStack); //I added the objects after all the values were finalized
array2.add(theQ);
}
else if(input.equals("2")) {
System.out.println("Enter the stock symbol:");
symbol2 = in.next();
System.out.println("Enter the number of shares you wish to sell:");
sellshares = in.nextInt();
String tempsymbol = "";
for(int i=0; i<array1.size(); i++) {
tempsymbol = (array1.get(i)).getSymbol();
if(symbol2.equals(tempsymbol)) {
System.out.println("The dollar cost averaged price per share (LIFO): " + (array1.get(i)).averageCost(sellshares));
System.out.println("The dollar cost averaged price per share (FIFO): " + (array2.get(i)).averageCost(sellshares));
}
}
}
else {
System.out.println("Input invalid ):");
System.exit(0);
}
System.out.println("Press 1 to continue working with your stocks or press anything else to finish up");
loopcheck = in.next();
}
System.out.println("END");
}
}
This is my queue class which works perfectly fine.
import java.util.LinkedList;
public class queue<E> {
private LinkedList<Double> linklist;
private String symbol;
private String name;
private int shares;
private Double price;
public queue(String symbol2, String name2, int shares2, Double price2) {
linklist = new LinkedList<Double>();
shares = shares2;
price = price2;
symbol = symbol2;
name = name2;
bigAdd(shares, price);
}
public String getName() {
return name;
}
public String getSymbol() {
return symbol;
}
public void add(Double e) {
linklist.add(e);
}
public Double take() {
return linklist.poll();
}
public void bigAdd (int shares2, Double price2) {
while(shares2>0) {
linklist.add(price2);
shares2--;
}
}
public double averageCost(int shares2) {
double average = 0;
int sizer = 0;
while(sizer < shares2) {
average = average + linklist.poll();
sizer++;
}
average = average/shares2;
return average;
}
And this is my stack class which also works fine.
import java.util.*;
public class stack {
private ArrayList<Double> stackArray = new ArrayList<Double>();
private int top;
private String symbol;
private String name;
private int shares;
private Double price;
public stack(String symbol2, String name2, int shares2, Double price2) {
symbol = symbol2;
name = name2;
shares=shares2;
price=price2;
top = -1;
bigPush(shares, price);
}
public double averageCost(int shares2) {
double average = 0;
int sizer = shares2;
while(sizer > 0) {
average = average + stackArray.get(top--);
sizer--;
}
average = average/shares2;
return average;
}
public void push(Double value) {
stackArray.add(++top, value);
}
public Double pop() {
return stackArray.get(top--);
}
public String getName() {
return name;
}
public String getSymbol() {
return symbol;
}
public void bigPush(int shares2, Double price2) {
while(shares2>0) {
stackArray.add(++top, price2);
shares2--;
}
}
public static void main(String[] args) {
stack theStack = new stack("Dave", "Franco", 2,10.0);
theStack.bigPush(2,20.0);
System.out.println(theStack.getSymbol());
}
}
Also heres an example of my output:
Press 1 to enter a new stock or press 2 to find the LIFO and FIFO dollar cost average for the number of shares sold
1
Enter the stock symbol:
DAVE
Enter the stock name:
FRANCO
Enter the number of shares bought:
5
Enter the price per share when purchased
5
Press 1 to continue entering new shares or press 2 to finish input for FRANCO
2
Press 1 to continue working with your stocks or press anything else to finish up
1
Press 1 to enter a new stock or press 2 to find the LIFO and FIFO dollar cost average for the number of shares sold
2
Enter the stock symbol:
DAVE
Enter the number of shares you wish to sell:
1
//AND THEN NOTHING HERE WHEN IT SHOULD RETURN AVERAGECOST()
Press 1 to continue working with your stocks or press anything else to finish up
Following your long code,
tt looks like it all boils down to a wrong usage of the Scanner class :
while(loopcheck.equals("1")) {
System.out.println("Press 1 to enter a new stock or press 2 to find the LIFO and FIFO dollar cost average for the number of shares sold");
input = in.next();
if(input.equals("1")) {
System.out.println("Enter the stock symbol:");
symbol = in.nextLine(); // problem here
in.nextLine();
this assigns an empty String to symbol, because it consumes the end of line of the previous in.next().
If you change it to :
while(loopcheck.equals("1")) {
System.out.println("Press 1 to enter a new stock or press 2 to find the LIFO and FIFO dollar cost average for the number of shares sold");
input = in.next();
in.nextLine();
if(input.equals("1")) {
System.out.println("Enter the stock symbol:");
symbol = in.nextLine();
it will work.
Edit :
It looks like you are aware of the need to sometimes call in.nextLine() without using its returned value, but you put in.nextLine() in the wrong place.

How to add multiple user input char and int into arrays in Java

I'm having a problem with my project in Java.
Here's the situation: the user will enter a character and integer of course code subj and units with a loop and restriction that indicates that when the total unit reaches "25" it will stop adding subj and course.
For example:
course code | subject | units
------------+-----------+-------
GE 111 | education | 3
GE 112 | history | 1
and so on..
After the user has entered the codes above, it will count all units and it will print to something thanks for the help. The code is too long, here is the most important part:
int[] a = new int[6];
Scanner sc = new Scanner(System.in);
System.out.println("\nenter units");
for (int j = 0; j < 9; j++) {
a[j] = sc.nextInt();
}
System.out.println("your subjects are:\n : ");
for (int i = 0; i < a.length; i++) {
System.out.println(a[i]);
}
System.out.print("\nEnter course code:" + a);
code = br.readLine().charAt(0);
System.out.print("\nenter course description");
subj = br.readLine().charAt(0);
System.out.print("\nenter units");
units = br.readLine().charAt(0);
case 2: break;
case 3: break;
case 4: break;
}
}
Are you trying to achieve this:
Main.java
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
//Make one Course container list to store a set of courses
List<Course> courses = new ArrayList<Course>();
//to store sum of units, intially 0
int unitSum = 0;
Course course = null;
while(true){
//make new course
course = new Course();
System.out.println("Enter course code:");
course.setSubjectCode(sc.nextInt());//store course code
System.out.println("Enter subject name:");
course.setSubjectName(sc.next());//store subject name
System.out.println("Enter units:");
course.setUnits(sc.nextInt());//store units
courses.add(course);//add Course to container
//take sum of units
unitSum += course.getUnits();
if(unitSum>=25)//end loop if sum reached 25
break;
}
System.out.println(courses);
sc.close();
}
}
Course.java
public class Course {
private int subjectCode;
private String subjectName;
private int units;
public Course() {
}
public int getSubjectCode() {
return subjectCode;
}
public void setSubjectCode(int subjectCode) {
this.subjectCode = subjectCode;
}
public String getSubjectName() {
return subjectName;
}
public void setSubjectName(String subjectName) {
this.subjectName = subjectName;
}
public int getUnits() {
return units;
}
public void setUnits(int units) {
this.units = units;
}
#Override
public String toString() {
return "Course [subjectCode=" + subjectCode + ", subjectName="
+ subjectName + ", units=" + units + "]";
}
}
this may help you..
Why don't you make object of what you need to work with? Then you can have it so much easier. Make a class and constructor of whathewer you want to use as entry new Entry(data1,data2,data3) work with all of those. It will help you when you make your program more complex.
To sum up the array to get total units
int sum=0;
for(int i:yourArray){
sum+=i;
}
The problem is that you work with all of your data as individual pars try to make some connection between them. Make object and put some functions in. (sum units), (get desc) etc. - it will be easy for you then to precede.

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