Develop Reference

Semicolon expected error in method header

I know that in method headers you aren't supposed to end it with a semicolon; however, all my method headers display the same error: ; expected. This is for the end of the header as well as between two parameters. How would I fix this?
import java.util.Scanner;
import java.text.DecimalFormat;
// This program will calculate the cost of someone's order at a coffee shop with applied possible discounts and tax
public class CoffeeShopWithMethods
{
public static void main (String [] args)
{
double cost = 0;
double discount = 0;
// Scanner allows user to enter values
Scanner user_input = new Scanner(System.in);
String username;
System.out.print("\nEnter your username: ");
username = user_input.next( );
System.out.print ("\nWelcome to Casey's Classic Coffee, " + username + "! \n");
//call methods
displayMenu();
displayOutput(cost, discount, Discounted_cost, tax, Total_cost);
System.out.println("\nThank you " + username + "! Have a nice day!");
}
//outputs the menu to the screen
public static void displayMenu()
{
System.out.println ("\n\tItem\t\tCost\n\t1. Coffee\t$1.50\n\t2. Latte\t$3.50\n\t3. Cappuccino\t$3.25\n\t4. Espresso\t$2.00");
}
//prompts the user to enter item number, returns user input
public static int getItemNumber(int number) //error: ; expected
{
int number;
Scanner number = new Scanner(System.in);
System.out.print ("\nPlease enter the desired item number: ");
number = user_input.nextInt();
return number;
}
//prompts user to enter quantity, returns user input
public static int getQuantity (int quantity) //error: ; expected
{
System.out.print ("\nPlease enter the quantity: ");
quantity = user_input.nextInt();
return quanity;
}
//takes the item number and quantity and returns the subtotal
public static double computeSubTotal (double cost) //error: ; expected
{
int number = getItemNumber(number);
int quantity = getQuantity(quantity);
// Used final double in order to make coffee shop items constant
final double COFFEE = 1.50;
final double LATTE = 3.50;
final double CAPPUCCINO = 3.25;
final double ESPRESSO = 2.00;
double cost = 0;
if (number == 1)
cost = quantity * COFFEE;
else if (number == 2)
cost = quantity * LATTE;
else if (number == 3)
cost = quantity * CAPPUCCINO;
else if (number == 4)
cost = quantity * ESPRESSO;
}
//takes the subtotal and returns true if the user earned a discount; otherwise, returns false
public static boolean discountCheck (double cost) //error: ; expected
{
boolean status;
if (cost >= 10)
{
status = true;
}
else if (cost < 10)
{
status = false;
}
return status;
}
//takes the subtotal and returns the dollar amount of the discount earned by the user
public static double computeDiscount (double cost, double discount) //error: ; expected
{
if (discountCheck() == true)
{
discount = cost * 0.10;
}
else if (discountCheck() != true)
{
discount = 0;
}
return discount;
}
//takes the subtotal and the discount amount and returns the price after the discount is applied
public static double computePriceAfterDiscount (double cost, double discount) //error: ; expected
{
double discount = 0;
double Discounted_cost = 0;
Discounted_cost = cost - discount;
return Discounted_cost;
}
//takes the prices after the discount is applied and tax rate and returns the tax amount
public static double computeTax(double Discounted_cost) //error: ; expected
{
tax = Discounted_cost * 0.07;
return tax;
}
//takes the price after the discount is applied and the tax amount and returns the final total
public static double computeTotal(double Discounted_cost, double tax) //says ; expected
{
Total_cost = Discounted_cost + tax;
return Total_cost;
}
//takes the subtotal, discount amount, price after discount, tax, and final total and displays all the lines of output to the user
public static void displayOutput(double cost, double discount, double Discounted_cost, double tax, double Total_cost) //says ; expected at the end of method header
{
//call methods
double cost = computeSubTotal(cost);
double discount = computeDiscount(cost, discount);
double Discounted_cost = computePriceAfterDiscount(cost, discount);
double tax = computeTax(Discounted_cost);
double Total_cost = computeTotal(Discounted_cost, tax);
System.out.printf ("\nTotal before discount and tax: $%.2f\n ", cost);
System.out.printf("\nCalculated discount: $%.2f\n", discount);
System.out.printf("\nTotal after special discount: $%.2f\n", Discounted_cost);
System.out.printf("\nTax: $%.2f\n", tax);
System.out.printf ("\nTotal cost: $%.2f\n", Total_cost);
}
} //error:reached end of the file while parsing

1)You are using the variables with out declaring:
for eg: compare this snippet with your code snippet.
public static double computeTotal(double Discounted_cost, double tax)
{
double Total_cost = Discounted_cost + tax;
return Total_cost;
}
2)You are invoking undefined methods.
for eg:
you are calling discountCheck() but you have defined like this.
and you have not initialized local variables before using
public static boolean discountCheck (double cost){
boolean status;
if (cost >= 10)
{
status = true;
}
else if (cost < 10)
{
status = false;
}
return status;
}
in the above method status should be initialized.
3) You are declaring duplicate variables that are already available to the methods via parameters.
see the code defined by you here:
public static void displayOutput(double cost, double discount, double Discounted_cost, double tax, double Total_cost)
{
//call methods
double cost = computeSubTotal(cost);
double discount = computeDiscount(cost, discount);
double Discounted_cost = computePriceAfterDiscount(cost, discount);
double tax = computeTax(Discounted_cost);
double Total_cost = computeTotal(Discounted_cost, tax);
System.out.printf ("\nTotal before discount and tax: $%.2f\n ", cost);
System.out.printf("\nCalculated discount: $%.2f\n", discount);
System.out.printf("\nTotal after special discount: $%.2f\n", Discounted_cost);
System.out.printf("\nTax: $%.2f\n", tax);
System.out.printf ("\nTotal cost: $%.2f\n", Total_cost);
}

I would start by extracting your MenuItem(s) into an enum like,
static enum MenuItem {
COFFEE("Coffee", 1.5), LATTE("Latte", 3.5), CAPPUCINO("Cappuccino",
3.25), ESPRESSO("Espresso", 2);
MenuItem(String name, double cost) {
this.name = name;
this.cost = cost;
}
double cost;
String name;
public String toString() {
return String.format("%s $%.2f", name, cost);
}
}
Then your compiler errors were mainly due to declaring duplicate local variable names. I was able to fix the compiler errors and produce something that looks like what you want with,
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter your username: ");
String username = scan.nextLine();
System.out.printf("Welcome to Casey's Classic Coffee, %s!%n", username);
displayMenu();
displayOutput(scan);
System.out.printf("Thank you %s! Have a nice day!", username);
}
// outputs the menu to the screen
public static void displayMenu() {
MenuItem[] items = MenuItem.values();
for (int i = 0; i < items.length; i++) {
System.out.printf("%d %s%n", i + 1, items[i]);
}
}
public static int getItemNumber(Scanner scan) {
System.out.println("Please enter the desired item number: ");
return scan.nextInt();
}
public static int getQuantity(Scanner scan) {
System.out.println("Please enter the quantity: ");
return scan.nextInt();
}
public static double computeSubTotal(Scanner scan) {
int number = getItemNumber(scan);
int quantity = getQuantity(scan);
return quantity * MenuItem.values()[number - 1].cost;
}
public static boolean discountCheck(double cost) {
return (cost >= 10);
}
public static double computeDiscount(double cost) {
if (discountCheck(cost)) {
return cost * 0.10;
}
return 0;
}
public static double computePriceAfterDiscount(double cost, double discount) {
return cost - discount;
}
public static double computeTax(double Discounted_cost) {
return Discounted_cost * 0.07;
}
public static double computeTotal(double Discounted_cost, double tax) {
return Discounted_cost + tax;
}
public static void displayOutput(Scanner scan) {
double cost = computeSubTotal(scan);
double discount = computeDiscount(cost);
double Discounted_cost = computePriceAfterDiscount(cost, discount);
double tax = computeTax(Discounted_cost);
double Total_cost = computeTotal(Discounted_cost, tax);
System.out.printf("Total before discount and tax: $%.2f%n", cost);
System.out.printf("Calculated discount: $%.2f%n", discount);
System.out.printf("Total after special discount: $%.2f%n",
Discounted_cost);
System.out.printf("Tax: $%.2f%n", tax);
System.out.printf("Total cost: $%.2f%n", Total_cost);
}

Here is your entire code corrected and working: http://ideone.com/ta0R21
I really recommend redesigning this. I suggest making use of global variable in some instances.
like the Scanner object. Instead of initializing a new Scanner each method call, use a global
one to handle the entire job

Add numbers in JAVA

How do I add the deposit numbers? Do I need some kind of loop (I´m new to JAVA)?.
public class BankAccount {
public static void main(String[] args) {
BankAccount account = new BankAccount();
account.deposit(1000, "Deposit 1");
account.deposit(2000, "Deposit 2");
System.out.println("Balance: " + account.getBalance());
account.deposit(3000, "Deposit 3");
account.deposit(4000, "Deposit 4");
System.out.println("Balance: " + account.getBalance());
}
private int currentBalance = 0;
private int getBalance() {
int finalBalance = depositAmount + currentBalance;
return finalBalance;
}
private int depositAmount;
public void deposit(int depositAmount) {
this.depositAmount = depositAmount;
}
}
Result should be:
Balance: 3000
Balance: 10000

Your deposit function is suspect. I think you want:
public void deposit(int depositAmount) {
this.currentBalance += depositAmount;
}
Note the +=: this will accumulate the deposit amount. You should also get rid of the class member depositAmount which is also causing bugs. Your getBalance function then reduces to
private/*ToDo - this will probably be public eventually*/ int getBalance() {
return currentBalance;
}
Two more issues though:
This function deposit is not called directly since you are calling a version that also takes a string. (I'm assuming that the function you give is called eventually though).
How will you model decimal values? Don't use a floating point as that will be imprecise. Use a currency type instead.

Well, this might work for you
public class BankAccount {
public static void main(String[] args) {
BankAccount account = new BankAccount();
account.deposit(1000);
account.deposit(2000);
System.out.println("Balance: " + account.getBalance());
account.deposit(3000);
account.deposit(4000);
System.out.println("Balance: " + account.getBalance());
}
private int currentBalance = 0;
private int getBalance() {
return this.currentBalance;
}
public void deposit(int depositAmount) {
this.currentBalance = this.currentBalance + depositAmount;
}
}

You are actually adding everything to the same object account . hence you are getting the result of all values inside it .(i.e) sum of all inputs 10000

Account class not working properly

public class AccountDriver {
public static void main(String[] args) {
// ID, Balance, Annual Interest Rate
Account number1 = new Account();
Account number2 = new Account(1122, 20000.00, 0.045);
// Default account
System.out.println("The Account ID is: " + number1.getId());
System.out.println("The Account Balance is: " + number1.getBalance());
// System.out.println("The Account Balance is: "+
// number1.getMontlyInterest());
System.out.println("");
// Ask to withdraw 2500
System.out.println("The Account ID is: " + number2.getId());
number2.withdraw(2500.00);
number2.deposit(3000.00);
System.out.println("Account Balance is " + number2.getBalance());
// System.out.println("The montly interest is : "+
// number2.getMontlyInterest());
System.out.println("");
}
}
public class Account {
private int id = 0;
private double balance = 0;
private double annualInterestRate = 0;
public Account(int id, double balance, double annualInterestRate) {
this.setId(id);
this.setBalance(this.balance);
this.setBalance(annualInterestRate);
}
public Account() {
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public double getBalance() {
return balance;
}
public void setBalance(double balance) {
this.balance = balance;
}
public double getAnnualInterestRate() {
return annualInterestRate;
}
public void setAnnualInterestRate(double annualInterestRate) {
this.annualInterestRate = annualInterestRate;
}
public double getMontlyInterest(double montlyInterest) {
// Given Formula
// double MontlyInterest= this.balance * get.MontlyInterestRate();
return montlyInterest;
}
public double getMontlyInterestRate(double montlyInterestRate) {
// Given Formula
montlyInterestRate = this.annualInterestRate / 12;
return montlyInterestRate;
}
double withdraw(double amount) {
return balance -= amount;
}
double deposit(double amount) {
return balance += amount;
}
}
I am getting error
The Account ID is: 0
The Account Balance is: 0.0
The Account ID is: 1122
Account Balance is 20500.0
Exception in thread "main" java.lang.Error: Unresolved compilation problem:
The method getMontlyInterestRate(double) in the type Account is not applicable for the arguments ()
at Account.getMontlyInterest(Account.java:41)
at AccountDriver.main(AccountDriver.java:21)

You did 2 small mistakes in your code.
In your constructor these 2 lines
this.setBalance(this.balance); // this.balance is the instance variable and not the parameter passed
^^^^ - this is not required, just use the balance parameter passed.
this.setBalance(annualInterestRate); // you are re-writing the balance with interest rate
^^^^^^^^^^ - You need to set annual interest rate and not the balance here.
should be
this.setBalance(balance); // sets the balance passed to the instance variable balance
this.setAnnualInterestRate(annualInterestRate); // sets the annual interest rate
Now since the annualInterestRate is set, you can get the monthly interest rate by modifying getMontlyInterestRate method like this.
public double getMontlyInterestRate() {
// Given Formula
return this.annualInterestRate / 12;
}
And you can print your monthly interest rate by uncommenting your System.out.println code.
System.out.println("The montly interest is : "+ number2.getMontlyInterestRate());
And the monthly interest method would look like this:
public double getMontlyInterest() { // no parameter required
// Given Formula
double MontlyInterest = this.balance * getMontlyInterestRate(); // balance multiplied by monthly interest rate
return MontlyInterest; // return the value
}
System.out.println("The montly interest is : "+ number2.getMontlyInterest());

bank account client in java with multiple classes

I am trying to make a bank account program, but I cannot figure out how to get all my variables visible to every class that I have, or how to make the withdrawal and deposit methods of my code visible. Can anyone look at my code and tell me what is wrong? I only want input and output in the client class.
Thanks
Client Class
public class Client {
public static void main(String args[]) {
Scanner input = new Scanner(System.in);
System.out.println("Enter your Name: ");
String cusName = input.nextLine();
System.out.println("Enter Account Type: ");
String type = input.next();
System.out.println("Enter Initial Balance: ");
int bal = input.nextInt();
BankAccount b1 = new BankAccount(cusName, num, type, bal);
int menu;
System.out.println("Menu");
System.out.println("1. Deposit Amount");
System.out.println("2. Withdraw Amount");
System.out.println("3. Display Information");
System.out.println("4. Exit");
boolean quit = false;
do {
System.out.print("Please enter your choice: ");
menu = input.nextInt();
switch (menu) {
case 1:
b1.deposit();
break;
case 2:
b1.withdraw();
System.out.println("Current Account Balance=" + Balance);
System.out.print("Enter withdrawal amount:");
amount = input.nextInt();
break;
case 3:
b1.display();
break;
case 4:
quit = true;
break;
}
} while (!quit);
}
}
Money Class
public class Money
{
static int accountNumber, Balance, amount;
Scanner input = new Scanner(System.in);
static String name, actype;
public int deposit() {
System.out.print("Enter depost amount:");
amount = input.nextInt();
if (amount < 0) {
System.out.println("Invalid");
return 1;
}
Balance = Balance + amount;
return 0;
}
int withdraw() {
if (Balance < amount) {
System.out.println("Not enough funds.");
return 1;
}
if (amount < 0) {
System.out.println("Invalid");
return 1;
}
Balance = Balance - amount;
return 0;
}
}
BankAccount Class
class BankAccount {
Scanner input = new Scanner(System.in);
static String name, actype;
static int bal, amt;
Random randomGenerator = new Random();
int accNo = randomGenerator.nextInt(100);
BankAccount(String name, int accNo, String actype, int bal) {
this.name = name;
this.accNo = accNo;
this.actype = actype;
this.bal = bal;
}
void display() {
System.out.println("Name:" + name);
System.out.println("Account No:" + accNo);
System.out.println("Balance:" + bal);
}
void dbal() {
System.out.println("Balance:" + bal);
}
}

Add Money to your BankAccount and create a getter method as:
class BankAccount {
Scanner input = new Scanner(System.in);
static String name, actype;
static int bal, amt;
Random randomGenerator = new Random();
int accNo = randomGenerator.nextInt(100);
Money money;
BankAccount(String name, int accNo, String actype, int bal) {
this.name = name;
this.accNo = accNo;
this.actype = actype;
this.bal = bal;
this.money = new Money();
}
public Money getMoney(){
return this.money;
}
.....
}
Use bankaccount.getMoney() to invoke deposit and withdraw as :
b1.getMoney().deposit();
b1.getMoney().withdraw();
In addition, I would advice to make the Money class attributes e.g. amount, accntType... non-static and set through through a constructor. Static variables are associated with class definition and hence you won't be abl to maintain them per Bank Account.

I'm not going to answer this question for you. Instead, I'm going to recommend that you read a bit more about Java programming concepts that will explain it to you, by default.
Here is one on encapsulation, which is the main concept that you're asking about
This is a great book on how to write code well, including things like keeping methods short
In particular, your main method should be broken into smaller pieces
Here's a stack overflow question that talks about it if you don't want to buy the book.
If you don't want to read any of these links, #YogendraSingh answered this question really well, use that answer.

Attributes to an object shouldn't be static, for example your "name, actype, bal and amt". Also I think your money class should exist and those methods could be in a bank account (you deposit/withdraw from a bank account).

Bank Account Program Issue

For my Java class, we need to make a bank account that has the methods of withdrawing, depositing money, and displaying current balance. In the Tester class, I want to make it ask for the name, the balance, then allow you to choose 1, 2, or 3. Then it repeats the option you choose until you say type "n". The problem is that running this code causes it to say after you deposit money "You deposited (amount of money deposited) in the account (name of account). Your new balance is (this)." The part where it says "this" is the exact same of the amount of money deposited. In other words, it doesn't add it, it just makes the new balance the same as the deposit, regardless of how much was in before. Any help? Thanks.
import java.io.*;
import java.util.*;
public class BankAccount
{
public BankAccount(double b, String n)
{
double balance = b;
String name = n;
}
public void deposit(double d)
{
balance += d;
}
public void withdraw(double w)
{
balance -= w;
}
public String nickname()
{
System.out.print("Enter a new name: ");
Scanner kbIn = new Scanner(System.in);
String n = kbIn.nextLine();
return n;
}
double balance;
String name;
}
And the tester class:
import java.io.*;
import java.util.*;
public class Tester
{
public static void main(String args[])
{
Scanner kbInLine = new Scanner(System.in);
Scanner kbIn = new Scanner(System.in);
System.out.print("Enter your name: ");
String name = kbInLine.nextLine();
System.out.print("Please enter balance: $");
double balance = kbIn.nextDouble();
BankAccount myAccount = new BankAccount(balance, name);
String proceed = "y";
while(proceed.equalsIgnoreCase("y"))
{
System.out.println("\nPlease pick a number. Would you like to...\n\t 1. Deposit\n\t 2. Withdraw\n\t 3. Print Balance\n");
int choice = kbIn.nextInt();
switch(choice)
{
case 1:
System.out.print("How much would you like to deposit?\n\t$");
double deposit = kbIn.nextDouble();
myAccount.deposit(deposit);
System.out.println("You have deposited $" + deposit + " into the account of " + name + ". The new balance is: " + myAccount.balance);
break;
case 2:
System.out.print("How much would you like to withdraw?\n\t$");
double withdraw = kbIn.nextDouble();
if(myAccount.balance - withdraw > 0)
{
myAccount.withdraw(withdraw);
System.out.println("You have withdrawn $" + withdraw + " from the account of " + name + ". The new balance is: " + myAccount.balance);
}
else
{
System.out.println("Sorry, you have insufficient funds for this operation. Your existing balance is $" + myAccount.balance);
}
break;
case 3:
System.out.print("The balance in the account of " + name + " is $" + myAccount.balance);
break;
}
System.out.print("\nWould you like to do another transaction? (Y/N)");
proceed = kbIn.next();
}
System.out.println("\nThank you for banking with us. Have a good day!");
}
}
What's really wierd is that I did a project before this one (it's actually a simplified version) where it deposits and then withdraws a predetermined, coded amount, then outputs the new bank balance, and it does it fine. But the code for BankBalance is the same. Here's the code for those.
BankAccount class is:
public class BankAccount
{
public BankAccount(String nm, double amt) // Constructor
{
name = nm;
balance = amt;
}
public void deposit(double d) // Sets up deposit object as balance += d
{
balance += d;
}
public void withdraw(double w) // Sets up withdraw object as balance -= w
{
balance -= w;
}
public double balance;
public String name;
}
And the Tester class is:
import java.io.*;
import java.util.*;
public class Tester
{
public static void main(String args[])
{
Scanner kbIn = new Scanner(System.in);
System.out.print("Enter your name:");
String name = kbIn.nextLine();
System.out.print("Enter the balance:");
double balance = kbIn.nextDouble();
BankAccount myAccount = new BankAccount(name, balance);
myAccount.deposit(505.22);
System.out.println(myAccount.balance);
myAccount.withdraw(100.00);
System.out.println("The " + myAccount.name + " account balance is, $" + myAccount.balance);
}
}

You're not actually initialising your balance member variable here:
public BankAccount(double b, String n)
{
double balance = b;
This creates a new local variable called balance, to which you assign the value of b. The member variable balance will remain 0 (the default) after this constructor is run.

public BankAccount(double b, String n)
{
double balance = b;
String name = n;
}
--->
public BankAccount(double b, String n)
{
this.balance = b;
this.name = n;
}

Or you can declare balance as static (data class field), and the methods that use this variable as static too.