The meal before tax and tip is 12.00, the tax percentage of the meal is 20% and the tip of the meal is 8%.
You need the use Scanner class to receive input from the user.
12.00
20
8
The expected output is:
15
I tried different ways especially with the code below but I'm getting different result. I can't get 15 as the expected out put.
enter public class MealSolution {
private static final Scanner scanner = new Scanner(System.in);
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
System.out.print("Enter cost of meal: ");
double meal_cost = scanner.nextDouble();
System.out.print("Enter the tip percent: ");
int tip_percent = scanner.nextInt();
System.out.print("Enter tax of meal: ");
int tax_percent = scanner.nextInt();
double tip = meal_cost * tip_percent/100;
double tax = meal_cost * tax_percent/100;
double cost = meal_cost + tip + tax;
long total_cost = Math.round(cost);
System.out.println(total_cost);
scanner.close();
}
}
To get the total cost, take the meal cost and add the tip and the tax.
double cost = meal_cost + tip + tax;
Related
I wrote the code to calculate the total based on the number of seats chosen by the user. The problem is when I enter a negative number for one of the seatings, the total is still calculated. Instead, when a negative number is inputted I want an error message to pop up and not calculate the total.
package javatheatreseating;
import java.util.Scanner;
public class JavaTheatreSeating {
public static final double PREMIUM_PRICE = 45.00;
public static final double STANDARD_PRICE = 30.00;
public static final double ECONOMY_PRICE = 21.00;
public static final double TAX_RATE = 0.0825;
public static final double SURCHARGE = 5.00;
public static void main(String[] args) {
int premiumSeats;
int standardSeats;
int economySeats;
double subTotal;
double salesTax;
double surCharge;
double total;
Scanner stdin = new Scanner(System.in);
//INPUT: number of seats sold
System.out.print ("Enter the number of Premium Seats Sold: ");
premiumSeats = stdin.nextInt();
System.out.print ("Enter the number of Standard Seats Sold: ");
standardSeats = stdin.nextInt();
System.out.print ("Enter the number of Economy Seats Sold: ");
economySeats = stdin.nextInt();
//PROCESS: i calculate the total and add the percent of tax based on the seats added
subTotal = premiumSeats * PREMIUM_PRICE + standardSeats * STANDARD_PRICE + economySeats * ECONOMY_PRICE;
salesTax = TAX_RATE * subTotal;
total = subTotal + salesTax + SURCHARGE;
//OUTPUT:
System.out.println();
System.out.println("Subtotal: " + subTotal);
System.out.println("Tax: " + salesTax);
System.out.println("surCharge: " + SURCHARGE);
System.out.println("Total: " + total);
}
}
put a while loop around each variable input and keep looping until the user gets it right. I didn't check if this compiles though.
while (true) {
try {
System.out.print ("Enter the number of Premium Seats Sold: ");
premiumSeats = stdin.nextInt();
if (premiumSeats >= 0){
break;
} else {
System.out.print ("Please Enter a positive integer.\n");
}
}
catch (Exception e){
System.out.print ("Please Enter a number.\n");
}
}
My first assignment is to develop a code that allows the user to input data for the distance in miles they wish to travel, the fuel efficiency, and the cost of gas. Then create a code in order to calculate the total cost of the trip.
I have all the code for all the input values but I'm having trouble with the equation itself. Java is not recognizing "/". I can't understand what I'm doing unless I need to add a bit more code for the equation to work.
import java.util.Scanner;
public class DrivingCost
{
public static void main(String args[])
{
Scanner s = new Scanner(System.in);
System.out.print("Please enter your distance (miles): ");
Scanner t = new Scanner(System.in);
System.out.print("Please enter vehicle's fuel efficiency (mpg): ");
Scanner u = new Scanner(System.in);
System.out.print("Please enter the price per gallon (dollars): ");
String distanceInMiles = s.nextLine();
System.out.println("The distance (miles): " + distanceInMiles);
String fuelEfficiency = t.nextLine();
System.out.println("Fuel efficiency (mpg):" + fuelEfficiency);
String pricePerGallon = u.nextLine();
System.out.println("Price per gallon (dollars): " + pricePerGallon);
double tripCost = (distanceInMiles / fuelEfficiency) * pricePerGallon;
System.out.println("The trip cost (dollars): " + tripCost);
}
}
This is the error I keep recieving:
DrivingCost.java:32: error: bad operand types for binary operator '/'
double tripCost = (distanceInMiles / fuelEfficiency) * pricePerGallon;
^
You're doing Math operation on String, you can't, you need double type
Double.parseDouble(sc.nextLine()); reads a line and parse to a double (benefits : avoid return line error in general, good habit to have)
sc.nextDouble() reads directly for a double
Use only one Scanner per source
Have a good order between print and scanner asking
Scanner sc = new Scanner(System.in);
System.out.print("Please enter your distance (miles): ");
String distanceInMiles = Double.parseDouble(sc.nextLine());
System.out.println("The distance (miles): " + distanceInMiles);
System.out.print("Please enter vehicle's fuel efficiency (mpg): ");
String fuelEfficiency = Double.parseDouble(sc.nextLine());
System.out.println("Fuel efficiency (mpg):" + fuelEfficiency);
System.out.print("Please enter the price per gallon (dollars): ");
String pricePerGallon = Double.parseDouble(sc.nextLine());
System.out.println("Price per gallon (dollars): " + pricePerGallon);
double tripCost = (distanceInMiles / fuelEfficiency) * pricePerGallon;
System.out.println("The trip cost (dollars): " + tripCost);
You are trying to do calculations with strings. You have to parse doubles out of your string inputs. Just change your equation line to this:
double tripCost = (Double.valueOf(distanceInMiles) / Double.valueOf(fuelEfficiency)) * Double.valueOf(pricePerGallon);
P.S. Proper input validation would be a good improvement. In case user provide incorrect input. Also, as mentioned in the comments there is no need to use multiple Scanners. One will be enough.
You can get distanceInMiles, fuelEfficiency and pricePerGallon in double using s.nextDouble().
After that you should be able to perform double operation on these variables.
public static void main(String args[])
{
Scanner s = new Scanner(System.in);
System.out.print("Please enter your distance (miles): ");
double distanceInMiles = s.nextDouble();
System.out.println("The distance (miles): " + distanceInMiles);
System.out.print("Please enter vehicle's fuel efficiency (mpg): ");
double fuelEfficiency = s.nextDouble();
System.out.println("Fuel efficiency (mpg):" + fuelEfficiency);
System.out.print("Please enter the price per gallon (dollars): ");
double pricePerGallon = s.nextDouble();
System.out.println("Price per gallon (dollars): " + pricePerGallon);
double tripCost = (distanceInMiles / fuelEfficiency) * pricePerGallon;
System.out.println("The trip cost (dollars): " + tripCost);
}
Assignment is to:
Display any welcome message at the top of the output screen
Create variables to hold the values for the price of a cup of lemonade.
Display the price per glass.
Ask the user for their name, and store it as a String object. Refer to the user by name, whenever you can.
Ask the user how many glasses of lemonade they would like to order. Save this as a variable with the appropriate data type.
Store the San Diego tax rate of 8% as a constant variable in your program.
Calculate the subtotal, total tax, and total price, and display it on the screen.
Ask the user how they would like to pay for the lemonade, and save the input as a char variable.
Ask the user to enter either 'm' for money, 'c' for credit card, or 'g' for gold
Using the DecimalFormat class, make all currency data printed to the screen display 2 decimal places, and also a '$" sign.
Need help figuring out how to get tax rate of 8% as a constant variable in my program
that way I can calculate the subtotal, total tax, and total price, and display it on the screen
So far this is what I have:
import java.util.Scanner;
import javax.swing.JOptionPane;
import java.text.DecimalFormat;
public class FirstProgram {
public static void main(String[] args) {
double cost = 7.55;
double amount = 7.55;
final double CA_SALES_TAX = 0.08;
int tax, subtotal, total;
subtotal = (int) (amount * cost);
tax = (int) (subtotal * CA_SALES_TAX);
total = tax + subtotal;
Scanner input = new Scanner(System.in);
double fnum = 7.55, tax1 = fnum * 0.08, answer = tax1 + fnum;
System.out.println("Welcome to the best Lemonade you'll ever taste! ");
System.out.println("My lemonade would only cost you a measly: $" + amount);
System.out.println("What is your name?");
String first_name;
first_name = input.nextLine();
System.out.println("Hi " +first_name+ ", how many glasses of lemonade would you like?");
fnum = input.nextDouble();
System.out.println("Subtotal: $" + (amount * fnum));
System.out.println("Tax: $" + (tax1 * CA_SALES_TAX));
tax1 = input.nextDouble();
Any help is appreciated
It looks like you already have the sales tax set as constant that is what the "final" keyword is being used for. As for your code i see some redundancies and am not sure as to why you are casting to integers. I made some mods for what I think you want it to do.
public static void main(String[] args) {
double cost = 7.55;
final double CA_SALES_TAX = 0.08;
double subtotal,tax,total;
Scanner input = new Scanner(System.in);
System.out.println("Welcome to the best Lemonade you'll ever taste! ");
System.out.println("My lemonade would only cost you a measly: $" + cost);
System.out.println("What is your name?");
String first_name = input.nextLine();
System.out.println("Hi " +first_name+ ", how many glasses of lemonade would you like?");
int fnum = input.nextInt();
//calc subtotal, tax, total
subtotal = fnum * cost;
tax = subtotal *CA_SALES_TAX;
total = tax + subtotal;
// print them all out
System.out.println("Subtotal: $" + (subtotal));
System.out.println("Tax: $" + (tax));
System.out.println("Total Price: $" + (total));
}
The code is below. The program runs a series of calculations based on data input by the user. My problem is that for the most important thing I'm looking for, total kg CO2 emissions, I continually get an answer of 0.0. What I need is a sum of the individual total emissions as calculated in each method, i.e. the values which are printed with the following: System.out.println(trans); System.out.println(elec); and System.out.println(food);
The total should be something like 25040 or whatever, depending on the value of the inputs provided by the user, but I'm constantly getting a total of 0.0., which is obviously false. Could have something to do with the way I've initialized my variables, or something to do with the limitations of returning values from methods. I just don't know what to do. How should I tackle this? All help greatly appreciated!
import java.util.Scanner;
public class CarbonCalc {
public static void main(String[] args) {
double trans = 0;
double elec = 0;
double food = 0;
giveIntro();
determineTransportationEmission(null);
determineElecticityEmission(null);
determineFoodEmission(null);
calculateTotalEmission(trans, elec, food);
//printReport(trans, elec, food);
}
//Gives a brief introduction to the user.
public static void giveIntro() {
System.out.println("This program will estimate your carbon footprint");
System.out.println("(in metric tons per year) by asking you");
System.out.println("to input relevant household data.");
System.out.println("");
}
//Determines the user's transportation-related carbon emissions.
public static double determineTransportationEmission(Scanner input) {
Scanner console = new Scanner(System.in);
System.out.println("We will first begin with your transportation-related carbon expenditures...");
System.out.print("How many kilometres do you drive per day? ");
double kmPerDay = console.nextDouble();
System.out.print("What is your car's fuel efficiency (in km/litre)? ");
double fuelEfficiency = console.nextDouble();
System.out.println("We now know that the numeber of litres you use per year is...");
double litresUsedPerYear = 365.00 * (kmPerDay / fuelEfficiency);
System.out.println(litresUsedPerYear);
System.out.println("...and the kg of transportation-related CO2 you emit must be...");
//Final calculation of transportation-related kgCO2 emissions.
double trans = 2.3 * litresUsedPerYear;
System.out.println(trans);
System.out.println("");
return trans;
}
//Determines the user's electricity-related carbon emissions.
public static double determineElecticityEmission(Scanner input) {
Scanner console = new Scanner(System.in);
System.out.println("We will now move on to your electricity-related carbon expenditures...");
System.out.print("What is your monthly kilowatt usage (kWh/mo)? ");
double kWhPerMonth = console.nextDouble();
System.out.print("How many people live in your home? ");
double numPeopleInHome = console.nextDouble();
System.out.println("The kg of electricity-related CO2 you emit must be...");
//Final calculation of electricity-related kgCO2 emissions.
double elec = (kWhPerMonth * 12 * 0.257) / numPeopleInHome;
System.out.println(elec);
System.out.println("");
return elec;
}
//Determines the user's food-related carbon emissions.
public static double determineFoodEmission(Scanner input) {
Scanner console = new Scanner(System.in);
System.out.println("We will now move on to your food-related carbon expenditures...");
System.out.print("In a given year, what percentage of your diet is meat? ");
double meat = console.nextDouble();
System.out.print("In a given year, what percentage of your diet is dairy? ");
double dairy = console.nextDouble();
System.out.print("In a given year, what percentage of your diet is fruits and veggies? ");
double fruitVeg = console.nextDouble();
System.out.print("In a given year, what percentage of your diet is carbohydrates? ");
double carbs = console.nextDouble();
//Final calculation of food-related kgCO2 emissions.
System.out.println("The kg of food-related CO2 you emit must be...");
double food = (meat * 53.1 + dairy * 13.8 + fruitVeg * 7.6 + carbs * 3.1);
System.out.println(food);
System.out.println("");
return food;
}
//Calculates total emissions across all sources.
public static double calculateTotalEmission(double trans, double elec, double food) {
System.out.println("Your total kg of CO2 emitted across all sources is equal to...");
double total = trans + elec + food;
System.out.println((double) total);
System.out.println("");
return total;
}
}
Ah!! Thank you very much Lyju. I did the following and it all worked well.
From this:
double trans = 0;
double elec = 0;
double food = 0;
To this:
double trans = determineTransportationEmission(null);
double elec = determineElecticityEmission(null);
double food = determineFoodEmission(null);
The second problem which popped up here had to do with not correctly passing the Scanner parameter to the multiple methods.
I fixed that by adding the following to the main method:
public static void main(String[] args) {
Scanner console = new Scanner(System.in);
double trans = determineTransportationEmission(console);
double elec = determineElecticityEmission(console);
double food = determineFoodEmission(console);
giveIntro();
calculateTotalEmission(trans, elec, food);
}
And because I had three scanner objects, one for each method, I simply removed the Scanners in each and can now pass a single Scanner from my main method to each of the others.
I have some code which I find to keep giving me a dividing by 0 error.
It is suppose to calculate the monthly payment amount!
import java.io.*;
public class Bert
{
public static void main(String[] args)throws IOException
{
//Declaring Variables
int price, downpayment, tradeIn, months,loanAmt, interest;
double annualInterest, payment;
String custName, inputPrice,inputDownPayment,inputTradeIn,inputMonths, inputAnnualInterest;
BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in));
//Get Input from User
System.out.println("What is your name? ");
custName = dataIn.readLine();
System.out.print("What is the price of the car? ");
inputPrice = dataIn.readLine();
System.out.print("What is the downpayment? ");
inputDownPayment = dataIn.readLine();
System.out.print("What is the trade-in value? ");
inputTradeIn = dataIn.readLine();
System.out.print("For how many months is the loan? ");
inputMonths = dataIn.readLine();
System.out.print("What is the decimal interest rate? ");
inputAnnualInterest = dataIn.readLine();
//Conversions
price = Integer.parseInt(inputPrice);
downpayment = Integer.parseInt(inputDownPayment);
tradeIn = Integer.parseInt(inputTradeIn);
months = Integer.parseInt(inputMonths);
annualInterest = Double.parseDouble(inputAnnualInterest);
interest =(int)annualInterest/12;
loanAmt = price-downpayment-tradeIn;
//payment = loanAmt*interest/a-(1+interest)
payment=(loanAmt/((1/interest)-(1/(interest*Math.pow(1+interest,-months)))));
//Output
System.out.print("The monthly payment for " + custName + " is $");
System.out.println(payment);
// figures out monthly payment amount!!!
}
}
the problem occurs when attempting to set the payment variable.
i don't understand why it keeps coming up with dividing by 0 error.
You have declared your variables as Int so 1/interest and 1/(interest*Math.pow(1+interest,-months)) will return 0. Change the type of your variables to float or double.
One suggestion to you, is that you should learn to "backwards slice" your code.
This means that when you see that you're getting a DivideByZeroException you should look at your code, and say, "why could this happen?"
In your case, let's look at this:
payment=(loanAmt/((1/interest)-(1/(interest*Math.pow(1+interest,-months)))));
So, now, Math.pow will never return anything zero (as it's a power), so it must be the case that interestis zero. Let's find out why:
interest =(int)annualInterest/12;
So now, integer division in Java truncates. This means that if you have .5 it will be cut off, and turned into zero. (Similarly, 1.3 will be truncated to 0).
So now:
annualInterest = Double.parseDouble(inputAnnualInterest);
This implies that you are passing in something that gets parsed to a value that is less than 12. If it were greater than 12 then you would get something else.
However, you might just be passing in an invalid string, for example, passing in "hello2.0" won't work!
This will be rounding always to 0. So it is trowing exception.
(1/interest)-(1/(interest*Math.pow(1+interest,-months)))));
Use float type instead of int. Learn how they works.
package computeloan;
import java.util.Scanner;
public class ComputeLoan {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print(" Enter Yearly Interest Rate : ");
double annualIntersetRate = input.nextDouble();
double monthlyIntersetRate = annualIntersetRate / 1200;
System.out.print(" Enter Number of years : ");
int numberOfYears = input.nextInt();
// Enter loan amount
System.out.print(" Enter Loan Amount : ");
double loanAmount = input.nextDouble();
double monthlyPayment = loanAmount * monthlyIntersetRate /(1-1/Math.pow(1+monthlyIntersetRate,numberOfYears*12 ));
double totalPayment = monthlyPayment * numberOfYears * 12;
//Calculate monthlyPaymeent and totalPayment
System.out.println(" The Monthly Payment Is : " +(int)(monthlyPayment*100) /100.0);
System.out.println(" The Total Payment Is : " +(int)(totalPayment*100) /100.0 );
}
}