So I need to get input from a user, which I have done, but then I need it to print out the giveFirstClassStamps amount and givePennyStamps amount, and I am at a loss as how to do this.
Any help or pointers in the right directions would be greatly appreciated.
import java.util.*;
/**
*/
public class StampMachine
{
public static final int FIRST_CLASS_STAMP_PRICE = 44;
private int balance;
/**
Constructs a stamp machine with a zero balance.
*/
public StampMachine()
{
balance = 0;
}
public static void main( String[ ] args)
{
Scanner input = new Scanner(System.in);
System.out.print("Enter 16-Digit Credit Card Number: ");
String cardNumber = input.nextLine();
System.out.print("Enter Month/Year of Expiration Date in MM/YY format: ");
String expirationDate = input.nextLine();
System.out.print("Stamp Purchase Amount: ");
int dollars = input.nextInt();
}
/**
Adds a given number of dollar bills into this machine.
#param dollars the number of dollar bills
*/
public void insert(int dollars)
{
balance = balance + 100 * dollars;
}
/**
Dispenses first class stamps for the inserted payment.
#return the number of first class stamps
*/
public int giveFirstClassStamps()
{
int firstClassStamps = balance / FIRST_CLASS_STAMP_PRICE;
balance = balance - firstClassStamps * FIRST_CLASS_STAMP_PRICE;
return firstClassStamps;
}
/**
Dispenses penny stamps for the inserted payment.
#return the number of penny stamps
*/
public int givePennyStamps()
{
int pennyStamps = balance;
balance = 0;
return pennyStamps;
}
You can create an instance of the class and then call the methods. Try the following after getting your input variables:
StampMachine sm = new StampMachine();
sm.insert(dollars);
You can continue using that same instance "sm" to call other methods as well.
In main, after getting the dollars
call insert method. Modify method sigantures to pass dollars entered by the user
call giveFirstClassStamps and assign the returned value to a local variable inside main
do the same for givePennyStamps and now print the values
Hope this helps.
Related
I created a mortgage calculator which works just fine but I don't want to use println() when asking for user input. I want the user to be able to type on the same line; however, everytime i use print() the user input is taken but the print statements do not get read into the output until the very end.
Example of Current Output
2000
4.12
10
Principal: Annual Interest Rate: Period (years): Mortgage: $20.36
Current Code
package demos1;
import java.text.NumberFormat;
import java.util.Scanner;
/**
*
* #author nicka
*/
public class MortgageCalculator {
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
final byte MONTHS = 12;
final byte PERCENTAGE = 100;
Scanner scanner = new Scanner(System.in);
System.out.print("Principal: ");
double principal = scanner.nextDouble();
System.out.print("Annual Interest Rate: ");
double annInterest = scanner.nextDouble();
System.out.print("Period (years): ");
double periodY = scanner.nextDouble();
double monInterest = (annInterest/MONTHS)/PERCENTAGE;
double periodM = periodY*MONTHS;
double n = Math.pow((1 + monInterest) ,periodM);
double mortgage = principal*((monInterest*n)/(n-1));
String formatMortgage = NumberFormat.getCurrencyInstance().format(mortgage);
System.out.println("Mortgage: " + formatMortgage);
}
}
I was using println() before and the problem didn't occur. I also tried moving some stuff around but still the same issue..
I am trying to create a bank account class with few tools such as Balance, Deposit and withdrawal. I created super class and two sub class. One of the sub class(checking account) needs to charge a 10$ fee after 2 transactions.
I am having small trouble in the following program. It is a minor part of the program and I tried everything but I can not think of the solution. The problem is marked with star box comment in the code. The bank account (super Class) class is attached for your reference.
It is charging the transaction fee even though withdrawal is failed due to unavailability of enough balance. I understand why it is doing that but can someone suggest any solution?
//This is the sub Class "Checking Account"
public class CheckingAccount extends BankAccount
{
//Private Instance Variablea
private double dTransFee;
private int iFreeCheckPerMonth;
private int iNumChecks;
//Constructor
public CheckingAccount(String sName, int iAccountNumber)
{
super(sName, iAccountNumber);
dTransFee = 10;
iFreeCheckPerMonth = 2;
iNumChecks=0;
}
//Overriding method from the Bank Account Class
public boolean bWithdrawl (double dMoney)
{
if (iNumChecks<2)
{
super.bWithdrawl(dMoney);
iNumChecks++;
iFreeCheckPerMonth--;
}
else
{
/****************************
* I DON'T KNOW HOW I CAN MAKE STATEMENT SUCH AS
* IF BWITHDRAL IS FALSE(FAILS) DON'T TAKE OUT 10 FROM BALANCE.
***************************/
super.bWithdrawl(dMoney);
dBalance = dBalance- dTransFee;
iNumChecks++;
iFreeCheckPerMonth--;
}
return false;
}
//Prints how many checks are left
public int FreeChecksLeft ()
{
return iFreeCheckPerMonth;
}
//Prints how many checks have been used
public int CheckUsed ()
{
return iNumChecks;
}
}
//Super Class
/**************************************************************
*Name: BankAccount
*Input:Name and account number. Deposit and withdrawal amount for methods
*Output: None
*Description:
* Date: 10/19/2017 Author: Apurva Gandhi
**************************************************************/
public class BankAccount
{
//Private Instance Variable
protected double dBalance;
protected int iAccountNum;
protected String sOwnerName;
//Constructor
public BankAccount (String sName, int iAccountNumber)
{
iAccountNum = iAccountNumber;
sOwnerName = sName;
}
/**************************************************************
*Name: deposit
*Input:amount of money
*Output: none
*Description: takes the amount of money and add the amount to the balance.
* Date: 10/19/2017 Author: Apurva Gandhi
**************************************************************/
//Method for deposit
public void deposit(double dMoney)
{
dBalance += dMoney;
}
/**************************************************************
*Name: Withdrawal
*Input:amount of money
*Output: none
*Description: takes the amount of money and subtracts the amount from the balance.
* Date: 10/19/2017 Author: Apurva Gandhi
**************************************************************/
//Method for Withdrawal
public boolean bWithdrawl (double dMoney)
{
if (dMoney <= dBalance)
{
dBalance -= dMoney;
}
return false;
}
//Method to get balance
public double getBalance()
{
return dBalance;
}
}
//Here is the tester for Checking Account
public class CheckingTester
{
public static void main(String[] args)
{
//Create Checking account
CheckingAccount ca1 = new CheckingAccount ("Apurva", 1000);
//Make deposit
ca1.deposit(500);
//Verify that it worked
System.out.println("After deposit the balance is: " + ca1.getBalance()+" Expected:500");
//Check #1
//Test a withdrawal
ca1.bWithdrawl(100);
//Verify that it worked
System.out.println("After withdrawal the balance is : " + ca1.getBalance()+ " Expected 400");
//Checks the number of free checks available for use
ca1.FreeChecksLeft();
System.out.println("Number of Free Checks left are: "+ca1.FreeChecksLeft()+ " Expected 1");
//Check how many checks have been used
ca1.CheckUsed();
System.out.println("The number of check used are: "+ ca1.CheckUsed()+(" Expected 1"));
//Check #2
ca1.bWithdrawl(100);
System.out.println("After withdrawal the balance is : " + ca1.getBalance()+ " Expected 300");
//Check 3
ca1.bWithdrawl(100);
System.out.println("After withdrawal the balance is : " + ca1.getBalance()+ " Expected 190");
//Check 4
ca1.bWithdrawl(200);
System.out.println("After withdrawal the balance is : " + ca1.getBalance()+ " Expected 190");
}
}
My dad and I narrowed it down to the object can't store the data. also, I'm new to java. The code is supposed to print in the console the first name, last name, grade, and grade average. I think the problem is in public double getCalcGraeAverage() but correct me if wrong, please.
import java.util.Scanner;
/**
* Write a description of class Student here.
*
* #author XXXX
* #version XXXX
*/
public class Student
{
String firstName;
String lastName;
int gradeLevel;
double gradeAverage;
int totalAssignments;
double totalPoints;
/**
* Create a new student with student's name, grade, and average
*/
public Student(String newFirstName, String newLastName, int newGradeLevel, double newGradeAverage)
{
firstName = newFirstName;
lastName = newLastName;
gradeLevel = newGradeLevel;
gradeAverage = newGradeAverage = 0.0;
}
/**
* Return the student's first name.
*/
public String getFirstName()
{
return firstName;
}
/**
* Return the student's last name.
*/
public String getLastName()
{
return lastName;
}
/**
* Return the grade level of the student.
*/
public int getGradeLevel()
{
return gradeLevel;
}
/**
* Calculates grade average.
*/
public double getCalcGradeAverage()
{
double gradeAverage = totalAssignments / totalPoints;
return gradeAverage;
}
public static void main (String[] args)
{
Student student1 = new Student ("XXXX", "XXXX", 11, 0.0);
System.out.println("The student's first name is: " + student1.getFirstName());
System.out.println("The student's last name is: " + student1.getLastName());
System.out.println("The student's grade level is: " + student1.getGradeLevel());
System.out.println("Please enter the total assignment points the student has earned: ");
Scanner input = new Scanner(System.in);
Double totalAssignments = input.nextDouble();
System.out.println("Please enter the number of assignments given: ");
double totalpoints = input.nextDouble();
System.out.println(student1.getFirstName() + " " + student1.getLastName() + " average grade is" + student1.getCalcGradeAverage());
}
}
In your code you are :
creating a Student student1 object
reading totalAssignments, totalpoints from System.in
calling student1.getCalcGradeAverage()
between steps 2 and 3 you have to set the fields totalAssignments, totalpoints of student to the values you read or they will retain their default values of zero. E.g.
student1.totalAssignments = totalAssignments;
student1.totalpoints = totalpoints;
Also, since totalAssignments is of type int, you probably want to read it as:
int totalAssignments = input.nextInt();
When writing your code, you declare variables for the student class with class scope.
int totalAssignments;
double totalPoints;
those class scope variable are used in the method :getCalcGradeAverage()
totalAssignments of Student and totalPoints of student are used in this method
When you create a new Student those variable are equals to zero because not affected by a value in your constructor.
in the main method when you writes :
Double totalAssignments =
you declare a new variable named "totalAssignments" with a method scope.When the method ends, the variable reference goes away and there is no way to access that variable any longer.
you can consider that the variable decalred is not the same that the student variable: student.totalAssignments is always equals to zero because no value affected to him.
Then assuming that you can do that :
student1.totalAssignments = input.nextInt();
student1.totalPoints = input.nextDouble();
The idea of this assignment is to have multiple methods interact with each other. I am asking the user for loan amount, interest rate and duration of loan. Then the program is supposed to have one method that calculates the monthly rate, one method that calculates and returns the monthly payment and a method to print the loan statement (amt borrowed,annual interest rate, number of months, and the monthly payment).
I am not receiving any errors in the editor but my program just asks for the three inputs from the user and does not print the loan statement. Any suggestions?
public class CarLoan {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// declare variables for main method
double loanAmount;//double value loan amount
double annualInterestRate;//double value interest rate
int numberOfMonths;//int value for number of months
double monthlyPayment;
Scanner keyboard = new Scanner(System.in);
System.out.println("Please enter the amount of your loan.");
loanAmount = keyboard.nextDouble();
System.out.println("Please enter the annual interest rate as a decimal. Ex. 7.5% = .075");
annualInterestRate = keyboard.nextDouble();
System.out.println("Please enter the number of months you have to pay back your loan.");
numberOfMonths = keyboard.nextInt();
}
public static double calcMonthlyInterestRate(double annualInterestRate){
double monthlyInterestRate;
monthlyInterestRate = (annualInterestRate/12);
return monthlyInterestRate;
}//end method CalcMonthlyInterestRate
public static double calcMonthlyPayment(double monthlyInterestRate, double loanAmount, int numberOfMonths ){
double monthlyPayment;
double calcMonthlyPayment;
calcMonthlyPayment = (monthlyInterestRate*loanAmount)/(1-(1+monthlyInterestRate)-numberOfMonths);
return monthlyPayment = calcMonthlyPayment;
}//end method CalcMonthlyPayment
public static void loanStatment (double loanAmount, double annualInterestRate, intnumberOfMonths, double monthlyPayment){
System.out.println("Your loan amount is " +loanAmount);
System.out.println(annualInterestRate);
System.out.println(numberOfMonths);
System.out.println(monthlyPayment);
}
}//end main method
}//end main method
I am not sure if some of my code is still redundant.
Since the main method is static and your CalcMonthlyInterestRate references your main method the CalcMonthlyInterestRate must also be static so that the two create a static reference to each other.
At the bottom of your post we see:
}//end main
}//end class
Class Methods referenced by the main method must also be inside its same class as well as being static. Once you start building your own classes and objects this won't always be the case
}//end main
public static double CalcMonthlyInterestRate(double annualInterestRate) {
double monthlyInterestRate;
monthlyInterestRate = (annualInterestRate/12);
return monthlyInterestRate;
}
}//end class
To capture a double using your method just call something like this in your main method:
double answer = CalcMonthlyInterestRate(/*some double variable here*/); //in main
Your method CalcMonthlyInterestRate need to be within your CarLoan class and not outside of it.
That's because you have it like this:
import java.util.Scanner;//instance of scanner class for input from user
public class CarLoan {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// declare variables for main method
double loanAmount;//double value loan amount
double annualInterestRate;//double value interest rate
int numberOfMonths;//int value for number of months
Scanner keyboard = new Scanner(System.in);
System.out.println("Please enter the amount of your loan.");
loanAmount = keyboard.nextDouble();
System.out.println("Please enter the annual interest rate as a decimal. Ex. 7.5% = .075");
annualInterestRate = keyboard.nextDouble();
System.out.println("Please enter the number of months you have to pay back your loan.");
numberOfMonths = keyboard.nextInt();
}
}//end main method
public static double CalcMonthlyInterestRate(double annualInterestRate)
{
double monthlyInterestRate;
monthlyInterestRate = (annualInterestRate/12);
return monthlyInterestRate;
}
There are a couple problems here... One is that //end main method is not really the end of the main method. It's the end of your class. All methods in Java have to be inside a class. Classes represent objects, and Java is "object-oriented". Each method on an object represents a "behavior" of that object. A behavior dangling applied to nothing is (most of the time) meaningless.
The "class, interface, or enum" expected means that where you are currently typing code, you can only put a class, an interface, or an enum. Those are the top level constructs of a Java program (unless you want to get technical with packages, etc...)
Putting the function inside the class (and fixing some code redundancy), we have:
import java.util.Scanner;//instance of scanner class for input from user
public class CarLoan {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// declare variables for main method
double loanAmount;//double value loan amount
double annualInterestRate;//double value interest rate
int numberOfMonths;//int value for number of months
Scanner keyboard = new Scanner(System.in);
System.out.println("Please enter the amount of your loan.");
loanAmount = keyboard.nextDouble();
System.out.println("Please enter the annual interest rate as a decimal. Ex. 7.5% = .075");
annualInterestRate = keyboard.nextDouble();
double monthlyInterestRate = CalcMonthlyInterestRate(annualInterestRate);
System.out.println("Please enter the number of months you have to pay back your loan.");
numberOfMonths = keyboard.nextInt();
} //end main method
public static double CalcMonthlyInterestRate(double annualInterestRate)
{
return annualInterestRate / 12;
} //end monthly interest method
} //end class
Also, methods in Java usually start with a lowercase letter.
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Closed 10 years ago.
So I am still fairly new to java. I have written this but am not sure as to why when I run it, the amounts will not add to what is set in the client.
For example: I enter 500 as starting balance, if I hit deposit, and type 500, and then hit case 3, it should say 1000 but it still says 500. And then If i hit withdraw, it says I have -500.
Any ideas? Thanks
package bankaccount;
import java.util.Random;
import java.util.Scanner;
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();
Random randomGenerator = new Random();
int accNo = randomGenerator.nextInt(100000);
System.out.println("Enter Initial Balance: ");
int balance = input.nextInt();
BankAccount b1 = new BankAccount(cusName, accNo, balance);
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:
System.out.print("Enter depost amount:");
Money.amount = input.nextInt();
b1.getDeposit();
break;
case 2:
System.out.println("Current Account Balance=" + b1.getBalance());
System.out.print("Enter withdrawal amount:");
Money.amount = input.nextInt();
b1.getWithdraw();
break;
case 3:
b1.display();
break;
case 4:
quit = true;
break;
}
} while (!quit);
}
public class Money
{
public static int accountNumber, balance=0;
static int amount;
static String name;
public void setDeposit(int amount) {
balance = balance + amount;
}
public int getDeposit()
{
balance = balance + amount;
if (amount < 0) {
System.out.println("Invalid");
}
return 1;
}
public void setBalance(int b)
{
b = balance;
}
public int getBalance()
{
return balance;
}
public void setWithdraw(int amount) {
balance = balance - amount;
}
public int getWithdraw()
{
balance = balance - amount;
if (balance < amount)
{
System.out.println("Not enough funds.");
return 1;
}
else if (amount < 0) {
System.out.println("Invalid");
return 1;}
else
return 0;
}
import java.util.*;
public class BankAccount extends Money {
static String name;
public static int balance, amount, acctNum;
Money customerMoney;
BankAccount(String name, int accNo, int bal) {
this.name = name;
this.acctNum = accNo;
this.balance = bal;
this.customerMoney = new Money();
}
void display() {
System.out.println("Name:" + name);
System.out.println("Account No:" + acctNum);
System.out.println("Balance:" + balance);
}
void displayBalance() {
System.out.println("Balance:" + balance);
}
public Money getMoney(){
return this.customerMoney;
}
}
The biggest problem is at statement balance=0
public static int accountNumber, balance=0;
^^^^^^^^^
Every time when you are going to insert amount, your balance is ZERO.
You should have used setDeposit(input.nextInt())
In public void setBalance(int b), b = balance; should have been balance = b;
Also, your amount, balance variables should be Float instead of int as balance/amount can be 23434.22.
I would remove all the public static int variables that you are using. These are going to cause confusion because it's much harder to follow what their values are as the program executes. Best to encapsulate your logic into BankAccount using private variables and public methods to modify them.
I would, personally, eliminate the Money class from your code. It's just going to cause confusion and with your simplified logic is not required. Let's assume the account holds some arbitrary count of 'money' but there is no real-life money actually backing it up - (kind of like real life, it's just 'numbers on a screen' right?) - in this case we wouldn't need the Money class, just an int for our BankAccount's balance.
Without trying to make too many changes to your underlying functionality, I rewrote as the below two classes:
A BankAccount class:
package banking;
public class BankAccount {
/**
* The balance of this account. <br/>
* Assumes integer money (Floating point math is horrible and who really
* needs pesky pence or cents right?!)
*/
private int balance;
/**
* The account number
*/
private final int acctNum;
/**
* Name of the account holder
*/
private final String name;
/**
* Construct our basic account with an account number, account holder and
* starting balance.
*
* #param name
* #param accNo
* #param bal
*/
public BankAccount(String name, int accNo, int bal) {
this.name = name;
this.acctNum = accNo;
this.balance = bal;
}
/**
* Make a deposit to this account by adding a fixed sum to the existing
* balance. <br/>
*
* #param amount
*/
public void deposit(int amount) {
if (amount <= 0) {
throw new IllegalArgumentException("You cannot deposit zero or less");
} else {
this.balance += amount;
}
}
/**
* Make a withdrawal from this account by subtracting a fixed amount from
* the existing balance. <br/>
*
* #param amount
*/
public void withdraw(int amount) {
if (amount > balance) {
throw new IllegalArgumentException("Insufficient Funds");
} else if (amount <= 0) {
throw new IllegalArgumentException("You cannot withdraw zero or less");
} else {
balance -= amount;
}
}
/**
* Get the account holder name.
*
* #return
*/
public String getName() {
return name;
}
/**
* Get the current account balance.
*
* #return
*/
public int getBalance() {
return balance;
}
/**
* Get the account identifier for this account.
*
* #return
*/
public int getAcctNum() {
return acctNum;
}
/**
* Debug print method.
*/
public void display() {
System.out.println("Name:" + name);
System.out.println("Account No:" + acctNum);
System.out.println("Balance:" + balance);
}
}
And the main class:
package banking;
import java.util.Random;
import java.util.Scanner;
public class BankMain {
public static void main(String args[]) {
Scanner input = new Scanner(System.in);
System.out.println("Enter your Name: ");
String customerName = input.nextLine();
Random randomGenerator = new Random();
int acctNo = randomGenerator.nextInt(100000);
System.out.println("Enter Initial Balance: ");
int balance = input.nextInt();
BankAccount acct = new BankAccount(customerName, acctNo, balance);
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;
int menu;
do {
final int transaction;
System.out.print("Please enter your choice: ");
menu = input.nextInt();
switch (menu) {
case 1:
System.out.print("Enter depost amount:");
transaction = input.nextInt();
acct.deposit(transaction);
break;
case 2:
System.out.println("Current Account Balance=" + acct.getBalance());
System.out.print("Enter withdrawal amount:");
transaction = input.nextInt();
try {
acct.withdraw(transaction);
} catch (IllegalArgumentException iaEx) {
System.out.println(iaEx.getMessage());
}
break;
case 3:
acct.display();
break;
case 4:
quit = true;
break;
}
} while (!quit);
}
}
This is still far from perfect, but I feel it's easier to follow for having the static variables and Money class removed.
You have many problems with the code e.g. none of your fields should be static, but the main one is that you have multiple duplicated fields.
e.g. In Money you have
public static int accountNumber, balance=0;
static int amount;
static String name;
and in BankAccount you have
static String name;
public static int balance, amount, acctNum;
Money customerMoney;
which means you have multiple fields called name, balance and amount. Some of the code uses the first group of fields and some of the code uses the second. You also have a customerMoney which is not updated directly.
To avoid confusion I suggest you have each field be non-static and in only one place. Remove the customerMoney as you might be tempted to use it ;)