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Need to set a maximum (100) and minimum (0), for this average test result program

Need to set a maximum (100) and minimum (0), for this average test result program. I understand that i would need to use '<' and'>' somewhere within my work however i am not sure how/where
import java.util.Scanner;
public class ExamResults {
public static void main(String args[]) {
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter the 5 exam results");
double ExamResult1 = 0.0;
ExamResult1 = Double.parseDouble(keyboard.nextLine());
double ExamResult2 = 0.0;
ExamResult2 = Double.parseDouble(keyboard.nextLine());
double ExamResult3 = 0.0;
ExamResult3 = Double.parseDouble(keyboard.nextLine());
double ExamResult4 = 0.0;
ExamResult4 = Double.parseDouble(keyboard.nextLine());
double ExamResult5 = 0.0;
ExamResult5 = Double.parseDouble(keyboard.nextLine());
double averageScore;
averageScore = ((ExamResult1 + ExamResult2 + ExamResult3 + ExamResult4 + ExamResult5)/5);
System.out.println("The average Score is" + averageScore);
}
}

Try something like:
double min = Math.min(Math.min(ExamResult1, ExamResult2), ExamResult3);//similarly for others
double max = Math.max(Math.max(ExamResult1, ExamResult2), ExamResult3);//similarly for others

I would do this:
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter the 5 exam results");
double[] examResults = new double[5];
double total = 0.0;
for (int i = 0; i < examResults.length; i++)
{
double value = Double.parseDouble(keyboard.nextLine());
while (value < 0 || value > 100)
{
System.out.println("Invalid score, try again");
value = Double.parseDouble(keyboard.nextLine());
}
examResults[i] = value;
total += value;
}
double averageScore;
averageScore = total / examResults.length;
System.out.println("The average Score is" + averageScore);

Code produces no output java

Im trying to write a code, that computes CD value, for every month.
Suppose you put 10,000 dollars into a CD with an annual percentage yield of 6,15%.
After one month the CD is worth:
10000 + 10000 * 6,15 / 1200 = 10051.25
After the next month :
10051.25 + 10051.25 * 6,15 / 1200 = 10102.76
Now I need to display all the results for the specific number of months entered by the user,
So
month1 =
month2 =
But whth this code I wrote, nothing is printed.
Can you see what's wrong?
Thanks in advance!
import java.util.Scanner;
public class CDValue {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("Enter an amount");
double amount = input.nextInt();
System.out.println ("Enter the annual percentage yield");
double percentage = input.nextDouble();
System.out.println ("Enter the number of months");
int months = input.nextInt();
double worth = amount + amount * percentage / 1200;
for (int i = 1; i < months; i++) {
while (i != months) {
amount = worth;
worth = amount + amount * percentage / 1200;
}
System.out.print(worth);

You do not modify neither i nor months in
while (i != months) {
....
}
so if the (i != months) condition is satisfied, the loop runs forever, and you never get to System.out.print statement.

for (int i = 1; i < months; i++) {
while (i != months) {
//you have to modify i or to modify the while condition.
}
if you don't modify i in the while you can't exit from the loop

Corrected code-
import java.util.Scanner;
public class CDValue {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("Enter an amount");
double amount = input.nextInt();
System.out.println ("Enter the annual percentage yield");
double percentage = input.nextDouble();
System.out.println ("Enter the number of months");
int months = input.nextInt();
double worth = amount + amount * percentage / 1200;
for (int i = 1; i <= months; i++)
{
System.out.print("Month " + i + " = " + worth);
amount = worth;
worth = amount + amount * percentage / 1200;
}
Note: If you want to print values for each month then the print statement should be inside the loop. You don't need two loops for the objective that you have mentioned above.

As you have been told your code won't get out of the while loop if you don't modify it. Simply remove the while loop. Your code should be like this:
import java.util.Scanner;
public class CDValue {
public static void main(String[] args){
Scanner input = new Scanner(System.in);
System.out.println("Enter an amount");
double amount = input.nextDouble();
System.out.println ("Enter the annual percentage yield");
double percentage = input.nextDouble();
System.out.println ("Enter the number of months");
int months = input.nextInt();
double worth = amount + amount * percentage / 1200;
for (int i = 1; i < months; i++) {
amount = worth;
worth = amount + amount * percentage / 1200;
}
System.out.print(worth);
}
}

Thanks! Solved it by using
{
System.out.print("Month " + i + " = " + worth);
amount = worth;
worth = amount + amount * percentage / 1200;
instead of while loop.
It works now :) Thanks so much!

Creating a Simple Commissions Calculator with Java

I am creating a simple commissions calculator, whereas, one can input the final sales price of an infinite amount of sales; then at the end it prints out the total amount of the commission plus a base pay rate ($200).
Here is my initial code:
import java.util.Scanner;
public class AssignmentsModule2_Program2 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// Intialization Phase
double sold = 0;
double soldCounter = 0;
double baseRate = 200.00;
double commissionRate = 0.09;
System.out.print("Enter total of sold item or -1 if done: ");
int value = input.nextInt();
while (sold != -1)
{
sold = sold + value;
soldCounter = soldCounter + 1;
System.out.print("Enter price of sold item or -1 if done: ");
value = input.nextInt();
}
double totalCommission = sold * commissionRate + baseRate;
System.out.printf("%nTotal pay for the week is: %d%n", sold);
}
}
Unfortunately, when I run the program an error code appears.
Here is the error code:
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:864)
at java.util.Scanner.next(Scanner.java:1485)
at java.util.Scanner.nextInt(Scanner.java:2117)
at java.util.Scanner.nextInt(Scanner.java:2076)
at assignmentsmodule2_program2.AssignmentsModule2_Program2.main(AssignmentsModule2_Program2.java:31)
Java Result: 1
Is there anyone out there who can lend some help?
Thanks.

You program is expecting an integer as input. The exception is thrown when a float or a char is used as input. I would use double variable:
import java.util.Scanner;
public class AssignmentsModule2_Program2 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// Intialization Phase
double sold = 0.0;
int soldCounter = 0;
double baseRate = 200.00;
double commissionRate = 0.09;
System.out.print("Enter total of sold item or -1 if done: ");
double value = input.nextDouble();
while (value > 0)
{
sold = sold + value;
soldCounter = soldCounter + 1;
System.out.print("Enter price of sold item or -1 if done: ");
value = input.nextDouble();
}
double totalCommission = sold * commissionRate + baseRate;
System.out.printf("%nTotal pay for the week is: %f%n", sold);
}
}

Java.Lang.Stringindexoutofboundsexception index out of range (0)

each time the program tries to loop, the error "java.lang.stringindexoutofboundsexception" comes up and highlights
ki=choice.charAt(0);
Does anyone know why that happens?. I'm brand new to programming and this has me stumped. Thanks for any help. Any solution to this problem would be amazing.
import java.util.Date;
import java.util.Scanner;
public class Assignment2
{
public static void main(String Args[])
{
Scanner k = new Scanner(System.in);
Date date = new Date();
double Wine = 13.99;
double Beer6 = 11.99;
double Beer12 = 19.99;
double Beer24 = 34.99;
double Spirit750 = 25.99;
double Spirit1000 = 32.99;
int WinePurchase = 0;
double WineTotal=0.0;
double GrandTotal = 0.0;
double GST = 0.0;
String complete = " ";
String choice;
char ki = ' ';
double Deposit750 = 0.10;
double Deposit1000 = 0.25;
System.out.println("------------------------------\n" +
"*** Welcome to Yoshi's Liquor Mart ***\nToday's date is " + date);
System.out.println("------------------------------------\n");
do{
if(ki!='W' && ki!='B' && ki!='S')
{
System.out.print("Wine is $13.99\nBeer 6 Pack is $11.99\n" +
"Beer 12 pack is $19.99\nBeer 24 pack is $34.99\nSpirits 750ml is $25.99\n"+
"Spirits 100ml is $32.99\nWhat is the item being purchased?\n"+
"W for Wine, B for beer and S for Spirits, or X to quit: ");
}
choice = k.nextLine();
ki= choice.charAt(0);
switch (ki)
{
case 'W':
{
System.out.print("How many bottles of wine is being purchased: ");
WinePurchase = k.nextInt();
System.out.println();
WineTotal = Wine*WinePurchase;
GST = WineTotal*0.05;
WineTotal += GST;
System.out.println("The cost of "+WinePurchase+ " bottles of wine including" +
" GST and deposit is " + WineTotal);
System.out.print("Is this customers order complete? (Y/N) ");
complete = k.next();
break;
}
}
}while (ki!='X');

The error means there the index "0" is outside the range of the String. This means the user typed in no input, such as the case when you start the program and hit the enter key. To fix this, simply add the following lines of code:
choice = k.nextLine();
if(choice.size() > 0){
//process the result
}
else{
//ignore the result
}
Let me know if this helps!

As you pointed out, the problem is in:
choice = k.nextLine();
ki= choice.charAt(0);
From the docs nextLine(): "Advances this scanner past the current line and returns the input that was skipped."
So in case the user pressed "enter" the scanner will go to the next line and will return an empty String.
In order to avoid it, simply check if choice is not an empty string:
if (!"".equals(choice)) {
// handle ki
ki= choice.charAt(0);
}

Try this:
Your problem was with the Scanner (k) you need to reset it everytime the loop start over.
import java.util.Date;
import java.util.Scanner;
public class Assignment2
{
public static void main(String Args[])
{
Scanner k;
Date date = new Date();
double Wine = 13.99;
double Beer6 = 11.99;
double Beer12 = 19.99;
double Beer24 = 34.99;
double Spirit750 = 25.99;
double Spirit1000 = 32.99;
int WinePurchase = 0;
double WineTotal=0.0;
double GrandTotal = 0.0;
double GST = 0.0;
String complete = " ";
String choice;
char ki = ' ';
double Deposit750 = 0.10;
double Deposit1000 = 0.25;
System.out.println("------------------------------\n" +
"*** Welcome to Yoshi's Liquor Mart ***\nToday's date is " + date);
System.out.println("------------------------------------\n");
do{
if(ki!='w' && ki!='b' && ki!='s')
{
System.out.print("Wine is $13.99\nBeer 6 Pack is $11.99\n" +
"Beer 12 pack is $19.99\nBeer 24 pack is $34.99\nSpirits 750ml is $25.99\n"+
"Spirits 100ml is $32.99\nWhat is the item being purchased?\n"+
"W for Wine, B for beer and S for Spirits, or X to quit: ");
}
k= new Scanner(System.in);
choice = k.nextLine();
ki= choice.toLowerCase().charAt(0);
switch (ki)
{
case 'w':
System.out.print("How many bottles of wine is being purchased: ");
WinePurchase = k.nextInt();
System.out.println();
WineTotal = Wine*WinePurchase;
GST = WineTotal*0.05;
WineTotal += GST;
System.out.println("The cost of "+WinePurchase+ " bottles of wine including" +
" GST and deposit is " + WineTotal);
System.out.print("Is this customers order complete? (Y/N) ");
complete = k.next();
break;
}
if(complete.toLowerCase().equals("y"))
break;
}while (ki!='x');
}
}

return issue for method

I am having an issue with a method returning to the main method. It is saying that amount in "return amount" cannot be resolved to a variable. Where am I off on this??
This is the message I get:
Multiple markers at this line
- Void methods cannot return a
value
- amount cannot be resolved to a
variable
Here is the code:
import java.util.Scanner;
public class Investment {
public static void main(String[]args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the amount invested: ");
double amount = input.nextDouble();
System.out.print("Enter the annual interest rate: ");
double interest = input.nextDouble();
int years = 30;
System.out.print(futureInvestmentValue(amount, interest, years)); //Enter output for table
}
public static double futureInvestmentValue(double amount, double interest, int years) {
double monthlyInterest = interest/1200;
double temp;
double count = 1;
while (count < years)
temp = amount * (Math.pow(1 + monthlyInterest,years *12));
amount = temp;
System.out.print((count + 1) + " " + temp);
}
{
return amount;
}
}

You curly braces are not correct. The compiler - and me - was confused about that.
This should work (at least syntactically):
import java.util.Scanner;
public class Investment {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the amount invested: ");
double amount = input.nextDouble();
System.out.print("Enter the annual interest rate: ");
double interest = input.nextDouble();
int years = 30;
System.out.print(futureInvestmentValue(amount, interest, years));
}
public static double futureInvestmentValue(
double amount, double interest, int years) {
double monthlyInterest = interest / 1200;
double temp = 0;
double count = 1;
while (count < years)
temp = amount * (Math.pow(1 + monthlyInterest, years * 12));
amount = temp;
System.out.print((count + 1) + " " + temp);
return amount;
}
}

Remove amount from its own scope As a start. Also from the method futureInvestmentValue, you take in amount as an argument but the value is never modified so you're returning the same value being passed which is most likely not the desired outcome.

remove return amount from its own scope
the method futureInvestmentValue... You can't modify any of the parameters inside the method so you have to declare another variable besides amount inside the method (maybe it's the temp variable you keep using) and return that instead
when you return something, the return statement is always inside the method. Never outside it while inside its own braces (never seen this before...)
import java.util.Scanner;
public class Investment {
public static void main(String[]args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the amount invested: ");
double amount = input.nextDouble();
System.out.print("Enter the annual interest rate: ");
double interest = input.nextDouble();
int years = 30;
System.out.print(futureInvestmentValue(amount, interest, years)); //Enter output for table
}
public static double futureInvestmentValue(double amount, double interest, int years) {
double monthlyInterest = interest/1200;
double temp;
double count = 1;
while (count < years) {
temp = amount * (Math.pow(1 + monthlyInterest,years *12));
System.out.print((count + 1) + " " + temp);
}
return amount;
}
}