public class Salary
{
public static void main (String[] args)
{
double currentSalary; // employee's current salary
double raise; // amount of the raise
double percentRaise; // percentage of the raise
double newSalary; // new salary for the employee
String rating; // performance rating
Scanner scan = new Scanner(System.in);
System.out.print ("Enter the current salary: ");
currentSalary = scan.nextDouble();
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
rating = scan.next();
if (rating.equals("Excellent"))
percentRaise = .06;
raise = (.06 * currentSalary);
else if (rating.equals("Good"))
percentRaise = .04;
raise = (.04 * currentSalary);
else if (rating.equals("Poor"))
percentRaise = .015;
raise = (.015 * currentSalary);
//Compute the raise using if ...
newSalary = currentSalary + raise;
//Print the results
NumberFormat money = NumberFormat.getCurrencyInstance();
System.out.println();
System.out.println("Current Salary: " + money.format(currentSalary));
System.out.println("Amount of your raise: " + money.format(raise));
System.out.println( "Your new salary: " + money. format (newSalary) );
System.out.println();
scan.close();
}
}
if i add { and } where the whitespace is then it says raise is not initialized. No matter what i do i cant seem to figure out to get it running. Right now it tells me to delete the else to let it run but if i do no matter i write excellent, good, or poor. It does .015 * salary so i cant get excellent or good to run.
if (rating.equals("Excellent"))
percentRaise = .06;
raise = (.06 * currentSalary);
else if (rating.equals("Good"))
Won't compile because Java sees this as...
if (rating.equals("Excellent"))
percentRaise = .06;
raise = (.06 * currentSalary);
else if (rating.equals("Good"))
Meaning that the compiler will complain about the else-if without a if statement.
The other problem you're having (when you place { } around the statements) is because Java makes no determination about what the initial value of a local variable will have.
This means Java simply doesn't know what to do with newSalary = currentSalary + raise; as there is no guarantee that raise will have a value assigned to it.
You could overcome this by adding an else condition to the end of your if-else block or simply supplying an initial value to your local variables...
double currentSalary = 0; // employee's current salary
double raise = 0; // amount of the raise
double percentRaise = 0; // percentage of the raise
double newSalary = 0; // new salary for the employee
String rating = ""; // performance rating
And while it might seem annoying, it's better then getting some completely random value which you would have to spend time trying to debug ;)
Updated
Remember, String#equals is case sensitive, this means "Excellent" is not equal to "excellent".
You could use String#equalsIgnoreCase instead
You need to wrap if statements into these things ---> "{}"
so its like this:
if(statement){
//then do someting
}else{
//then do something else
}
You can only write if statements without braces if it contains only one command, if you have more than one command (more than one line) you need to enclose those commands in braces
You have to make sure that if your if statement contains more than one line of code, it is wrapped in braces.
public class Salary
{
public static void main (String[] args)
{
double currentSalary; // employee's current salary
double raise; // amount of the raise
double percentRaise; // percentage of the raise
double newSalary; // new salary for the employee
String rating; // performance rating
Scanner scan = new Scanner(System.in);
System.out.print ("Enter the current salary: ");
currentSalary = scan.nextDouble();
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
rating = scan.next();
if (rating.equals("Excellent"))
{
percentRaise = .06;
raise = (.06 * currentSalary);
}
else if (rating.equals("Good"))
{
percentRaise = .04;
raise = (.04 * currentSalary);
}
else if (rating.equals("Poor"))
{
percentRaise = .015;
raise = (.015 * currentSalary);
}
//Compute the raise using if ...
newSalary = currentSalary + raise;
//Print the results
NumberFormat money = NumberFormat.getCurrencyInstance();
System.out.println();
System.out.println("Current Salary: " + money.format(currentSalary));
System.out.println("Amount of your raise: " + money.format(raise));
System.out.println( "Your new salary: " + money. format (newSalary) );
System.out.println();
scan.close();
}
}
Related
I have this bit of code to return to the beginning of the program if an answer is not expected.
...
else // returns to start for unsatisfactory
{
System.out.println();
System.out.println();
System.out.println("Check your spelling and try again");
main (args);
}
...
however when I enter a different word then go through again and enter an expected word the program outputs two different results
Current Salary: $100.00
Amount of your raise: $4.00
Your new salary: $104.00
Current Salary: $100.00
Amount of your raise: $0.00
Your new salary: $100.00
I tried using an else if statement to possibly eliminate that as a cause but it caused the same thing.
import java.util.Scanner;
import java.text.NumberFormat;
public class Salary {
public static void main (String[] args) {
double currentSalary; // employee's current salary
double raise = 0.0; // amount of the raise
double newSalary; // new salary for the employee
String rating; // performance rating
Scanner scan = new Scanner(System.in);
System.out.print ("Enter the current salary: ");
currentSalary = scan.nextDouble();
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
rating = scan.next();
// Computes raise with if-else
if ((rating.equals("Excellent")) || (rating.equals("excellent"))) {
// calculates raise for excellent
raise = .06 * currentSalary;
}
else if ((rating.equals("Good")) || (rating.equals("good"))) {
// calculates raise for good
raise = .04 * currentSalary;
}
else if ((rating.equals("Poor")) || (rating.equals("poor"))) {
// calculates raise for poor
raise = .015 * currentSalary;
}
else {
// returns to start for unsatisfactory
System.out.println();
System.out.println();
System.out.println("Check your spelling and try again");
main (args);
}
newSalary = currentSalary + raise;
// Print the results
NumberFormat money = NumberFormat.getCurrencyInstance();
System.out.println();
System.out.println("Current Salary: " + money.format(currentSalary));
System.out.println("Amount of your raise: " + money.format(raise));
System.out.println("Your new salary: " + money.format(newSalary));
System.out.println();
}
}
That is because you call main recursively (which is not considered good practice BTW) when you don't get an expected input. After you enter (the 2nd time) an expected input, the remainder of the initial main must still be executed which will then work with a raise of 0.0 as the input was invalid.
A pragmatic solution for your issue could be avoiding the recursive call to main and wrap e.g. the input validation in a loop like so
...
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
while (true) {
rating = scan.next();
if ((rating.equals("Excellent")) || (rating.equals("excellent")))
{
raise = .06 * currentSalary; break;
}
else if ((rating.equals("Good")) || (rating.equals("good")))
{
raise = .04 * currentSalary; break;
}
else if ((rating.equals("Poor")) || (rating.equals("poor")))
{
raise = .015 * currentSalary; break;
}
else
{
System.out.println();
System.out.println();
System.out.println("Check your spelling and try again");
}
}
...
You're not returning after you call main (args); so every iteration of your program will continue.
You should add return; after main (args);
{
System.out.println();
System.out.println();
System.out.println("Check your spelling and try again");
main (args);
return;
}
edit: as pointed out by John3136 you shouldn't be calling main (args) recursively either.
That (second) call you make to main() "finishes" and comes back out to the "first" one that was invoked by starting the program.
So the first lot of results are from your explicit call to main(). The second lot is from when that call ends and you are back to where you called from.
Calling main() recursively is not recommended. You should use a while loop inside main(). i.e. Keep asking for input until you know the input is valid, and then actually use it.
You should not call main recursively.you should use do while loop as I update code and it's working fine.
import java.util.Scanner;
import java.text.NumberFormat;
public class Salary {
public static void main (String[] args) {
double currentSalary; // employee's current salary
double raise = 0.0; // amount of the raise
double newSalary; // new salary for the employee
String rating; // performance rating
boolean flag=false; // to check input
Scanner scan = new Scanner(System.in);
do{
System.out.print ("Enter the current salary: ");
currentSalary = scan.nextDouble();
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
rating = scan.next();
// Computes raise with if-else
if ((rating.equals("Excellent")) || (rating.equals("excellent"))) // calculates raise for excellent
{
raise = .06 * currentSalary;
flag=true;
}
else if ((rating.equals("Good")) || (rating.equals("good"))) // calculates raise for good
{
raise = .04 * currentSalary;
flag=true;
}
else if ((rating.equals("Poor")) || (rating.equals("poor"))) // calculates raise for poor
{
raise = .015 * currentSalary;
flag=true;
}
else // returns to start for unsatisfactory
{
System.out.println();
System.out.println();
System.out.println("Check your spelling and try again");
flag=false;
}
}while(!flag);
newSalary = currentSalary + raise;
// Print the results
NumberFormat money = NumberFormat.getCurrencyInstance();
System.out.println();
System.out.println("Current Salary: " + money.format(currentSalary));
System.out.println("Amount of your raise: " + money.format(raise));
System.out.println("Your new salary: " + money.format(newSalary));
System.out.println();
}
}
You may want to consider another approach. Either terminate the problem in case the input is invalid or try to repair it. The following example is for the "repair" approach,
public class Salary {
public static void main(String[] args) {
IPM ipm;
if (verify(args)) {
ipm = new IPM(args);
} else {
Scanner scan = new Scanner(System.in);
String[] update;
do {
update = repair(scan);
} while (!verify(update)); // You may want a loop count as well...
ipm = new IPM(update);
}
ipm.print();
}
public static boolean verify(String[] s) {
return IPM.verify(s);
}
public static String[] repair (Scanner s) {
// Request new input and store it in an array of strings.
// This method does not validate the input.
}
}
public class IPM {
double currentSalary;
double raise = 0.0;
double newSalary;
String rating;
IPM(String[] input) {
// Set attributes of IPM.
}
public static boolean verify(String[] s) {
//Determine if the input is valid.
}
public void print() {
// Print IPM object.
}
}
Note that the call to IPM.verify() from salary. This should be a part of the responsibility of IPM since Salary is not require to know anything about main. Also, the class IPM might change and a call to IPM.verify() will not require that all classes which verifies the IPM are changed as well.
New here (and to Java!). I've searched around the site for an answer to my problem but came up naught. This program executes up to the scan.nextDouble statement.
If I enter a salary value such as "8," I get:
/////OUTPUT/////
Enter the performance rating (Excellent, Good, or Poor):
Current Salary: $8.00
Amount of your raise: $0.00
Your new salary: $8.00
/////END OF OUTPUT/////
So obviously, my following scan.nextLine and all the if-else statements are bypassed. What am I missing?
import java.util.Scanner;
import java.text.NumberFormat;
public class Salary
{
public static void main(String[] args)
{
double currentSalary; // employee's current salary
double raise = 0; // amount of the raise
double newSalary = 0; // new salary for the employee
String rating; // performance rating
String rating1 = new String("Excellent");
String rating2 = new String("Good");
String rating3 = new String("Poor");
Scanner scan = new Scanner(System.in);
System.out.print ("Enter the current salary: ");
currentSalary = scan.nextDouble();
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
rating = scan.nextLine();
// Compute the raise using if ...
if (rating.equals(rating1))
raise = .06;
else
if (rating.equals(rating2))
raise = .04;
else
if (rating.equals(rating3))
raise = .015;
else
newSalary = currentSalary + currentSalary * raise;
// Print the results
{
NumberFormat money = NumberFormat.getCurrencyInstance();
System.out.println();
System.out.println("Current Salary: " + money.format(currentSalary));
System.out.println("Amount of your raise: " + money.format(raise));
System.out.println("Your new salary: " + money.format(newSalary));
System.out.println();
}
}
}
When you scan input using scanner.nextDouble() it takes only the float value and leaves the new line character in the buffer so after that when you do scanner.nextLine(() it takes the new line character and returns empty string.Put another scanner.nextLine() before scanning the next line to eat up the new line character
currentSalary = scan.nextDouble();
System.out.print ("Enter the performance rating (Excellent, Good, or Poor): ");
scan.nextLine();
rating = scan.nextLine();
Scanner.nextDouble() just reads the next available double value and does not by itself point to next line.
use a dummy scanner.nextLine() before your actual one. that lets your cursor point to next line from which your scanner.nextline() takes the input.
-cheers :)
I'm in a programming class in high-school, and I was given an assignment to make a basic subtotal and top calculator, but I work at a restaurant, so it seemed a little pointless to make a calculator that only let you read in one food. So I tried to make it able to take in multiple food items and add them to one price variable. Sorry if some of this code may seem inefficient or redundant. It's only high-school of course.
The issue is, when I run it, it gets up to the asking if there was another food item the user would like to add, and when I type in "Yes" or "No", the program does nothing. Keeps running, but goes no further. Any explanations?
import java.text.NumberFormat;
import java.util.Scanner;
public class Price {
/**
* #param args
*/
public static void main(String[] args) {
final double taxRate = .0887; //8.87% Tax Rate
double tipRate;
int quantity1;
Scanner kb = new Scanner(System.in);
double subtotal, tax, tip, totalCost1, unitPrice1 = 0;
String done;
System.out.println ("How many of the first item did you get?: ");
quantity1 = kb.nextInt();
for (int i = 0; i < quantity1; i++)
{
System.out.println ("What was the price of that single item "+(i+1) + ": ");
unitPrice1 = kb.nextDouble();
System.out.println ("Was there another food item you'd like to add?: ");
done=kb.next();
while (done.equalsIgnoreCase("Yes"));
}
System.out.println ("What percent would you like to tip? (Formatted like 0.10 for 10%, 0.20 for 20%, etc.): ");
tipRate = kb.nextDouble();
subtotal= quantity1 * unitPrice1;
tax = subtotal * taxRate;
totalCost1 = subtotal + tax;
tip = totalCost1 * tipRate;
totalCost1 = totalCost1 + tip;
//Formatting
NumberFormat money = NumberFormat.getCurrencyInstance();
NumberFormat tipMoney = NumberFormat.getCurrencyInstance();
NumberFormat taxPercent = NumberFormat.getPercentInstance();
NumberFormat tipPercent = NumberFormat.getPercentInstance();
System.out.println ("Your total before tax is: " + money.format(subtotal));
System.out.println ("The tax is " + money.format(tax) + " at " + tipPercent.format(taxRate));
System.out.println ("The tip at " + tipPercent.format(tipRate) + " is " + tipMoney.format(tip));
}
}
You have an infinite loop here:
while (done.equalsIgnoreCase("Yes"));
Once you enter Yes, it will keep sitting there and doing nothing because the value of done is Yes and never changes.
Also your loop structure is a bit odd. Your outer for loop runs as many times as the quantity of the first item. But shouldn't you only be multiplying that number to the cost? Because you are either running the loop for as long as the number of items the user entered (by asking them up front) or you don't ask them the total number of items and simply ask them to enter Yes if they want to add more items; you can't really do both.
Your loop should probably look something like this:
String input = "Yes";
while(input.equalsIgnoreCase("Yes")) {
System.out.println ("How many of the first item did you get? ");
quantity1 = kb.nextInt();
System.out.println ("What was the price of that single item? ");
unitPrice1 = kb.nextDouble();
//total += unitPrice1 * quantity1 - you don't have this in your code, but this is where you would be calculating the running total
System.out.println("Was there another food item you'd like to add? ");
input = kb.next();
}
you need to exit for loop when user enters yes, so you can use label here like below:
outerloop:
for (int i = 0; i < quantity1; i++)
{
System.out.println ("What was the price of that single item "+(i+1) + ": ");
unitPrice1 = kb.nextDouble();
System.out.println ("Was there another food item you'd like to add?: ");
done=kb.next();
while (done.equalsIgnoreCase("Yes")){
break outerloop;
}
}
Your current code does not do anything inside the while loop if you don't enter yes. And if you enter yes it will be stuck in infinite loop because of your while loop. This is not the efficeint way of looping, but this code will have least change in your current code.
You're while loop is doing nothing, you had given it a condition, but it has no instruction.
Try something like this..(sorry for my rusty java)
'public static void main(String[] args) {
//variable declaration
bool running = true
final double taxRate = .0887; //8.87% Tax Rate
double tipRate;
int quantity1;
Scanner kb = new Scanner(System.in);
double subtotal, tax, tip, totalCost1, unitPrice1 = 0;
String done;
while(running = true){
System.out.println ("How many of the first item did you get?: ");
quantity1 = kb.nextInt();
for (int i = 0; i < quantity1; i++)
{
System.out.println ("What was the price of that single item "+(i+1) + ": ");
unitPrice1 = kb.nextDouble();
System.out.println ("Was there another food item you'd like to add?: ");
done=kb.next();
if(done.equalsIgnoreCase("No")){
running = false
//Allows you to break out of the while loop if the user does not want to add anything else
//DO NOT USE BREAK STATMENTS, IT IS A POOR PROGRAMMING PRACTICE.
};//end if
}//end for
}//end while
System.out.println ("What percent would you like to tip? (Formatted like 0.10 for 10%, 0.20 for 20%, etc.): ");
tipRate = kb.nextDouble();
//You should comment whats going on here
subtotal= quantity1 * unitPrice1;
tax = subtotal * taxRate;
totalCost1 = subtotal + tax;
tip = totalCost1 * tipRate;
totalCost1 = totalCost1 + tip;
//Formatting
NumberFormat money = NumberFormat.getCurrencyInstance();
NumberFormat tipMoney = NumberFormat.getCurrencyInstance();
NumberFormat taxPercent = NumberFormat.getPercentInstance();
NumberFormat tipPercent = NumberFormat.getPercentInstance();
//Output
System.out.println ("Your total before tax is: " + money.format(subtotal));
System.out.println ("The tax is " + money.format(tax) + " at " + tipPercent.format(taxRate));
System.out.println ("The tip at " + tipPercent.format(tipRate) + " is " + tipMoney.format(tip));
}//end main
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 );
}
}
Alright so I'm trying to get the user to input either the word "random" or a number (0.01) for a sales tax and my prompt can only use either keybd.next() or keybd.nextDouble() so how would I easily do this?
public void calculateSalesReceipt(){
System.out.println("Enter the sales tax percentage (ex. 0.08 for 8%) or type \"random\" for a random number: ");
double tax = keybd.nextDouble();
if(tax < 0){
System.out.println("You must enter a value equal to or greater than 0!");
}else{
getFinalPricePreTax();
total = total;
taxcost = total * tax;
double finaltotal = total * taxcost;
System.out.println("Sales Receipt");
System.out.println("-------------");
for(Item currentProduct : shoppingBag){
System.out.println(currentProduct.getName() + " - " + currentProduct.getUnits() + " units " + " - $" + currentProduct.getCost());
}
System.out.println("Total cost: $" + total);
System.out.println("Total tax: $" + taxcost);
System.out.println("Total cost with tax: $" + finaltotal);
}
Thanks
Assuming keybd is a Scanner
http://download.oracle.com/javase/6/docs/api/java/util/Scanner.html
You need to use hasNextDouble() to determine if it's a double or not and then act accordingly.
Option B (though you say your requirements exclude this) is to simply read it as a String then do the conversion afterward with Double.valueOf(String) or Double.parseString(String) static methods and catching the NumberFormatException to determine validity.
Edit based on comments from OP:
System.out.println("Enter the sales tax ... blah blah");
if (keybd.hasNextDouble())
{
double tax = keybd.nextDouble();
// Do double stuff
}
else
{
// Get String and Do string stuff
}
You can use Double.parseDouble(String) to convert a string value to a double. If the string does not represent a double value, a NumberFormatException will be thrown.
double d;
if ("random".equals(string)) {
d = 4.0; // random
} else {
try {
d = Double.parseDouble(string);
} catch (NumberFormatException e) {
// !
}
}
You can use keybd.next() to grab the token as a string. Then check if its a double.
Sample code:
String input= keybd.next();
try{
Double input= Double.parseDouble(input);
//execute code with double variable
} catch (ParseException ex){
//call string handler code
}