Exeption in thread "main"....

[nightrise420]

exception in thread "main" java.lang.noclassdefounderror: assign 4.
i get this error message. I'm trying to write a program that promps user for item price and with the input i sum it up and display it using system.out.println. This is what i have so far. thank you


import java.util.Scanner;
public class Assign4
{
public static void determineClassAverage()
{
Scanner input = new Scanner( System.in );

double total;
double itemCounter;
double price;
double average;
double commission;

total = 0;
itemCounter = 0;

System.out.print( "Enter grade or -1 to quit: " );
price = input.nextInt();

while ( price != -1 )
{
total = total + price;
itemCounter = itemCounter + 1;

System.out.print( "Enter item value or -1 to quit: " );
price = input.nextInt();

average = (double) total / itemCounter;
commission = total * .9;

System.out.printf( "\nItems sold: \n",
itemCounter);
System.out.printf( "\nTotal amount: \n", total );
System.out.printf( "\nCommission: \n",
commission);
System.out.printf( "Class average is %.2f\n", average );
}
}
}

[j2me64]

i just started your class replacing the code from the last printf with

            System.out.printf("Class average is %.2f\n", average);
        }
    }
    public static void main(String[] args) {
        new Assign4().determineClassAverage();
    }
}

and i could start the method determineClassAverage without errors.

[JosAH]

exception in thread "main" java.lang.noclassdefounderror: assign 4.

The name of the class is Assign4 (with a capital A) not assign4 (lowercase a).

kind regards,

Jos

ps. I guess that the space in 'assign 4' is a forum software hiccup.

[nightrise420]

when i run it, it only promps me twice and the program ends with the information.
Also the result number of items sold doesn't appear for some reason.
And my System.out.printf( "\nEarnings: $%.2f", earnings) results in this message.
"Earnings: $310.70Enter item value or -1 to quit: "

[nightrise420]

Nevermind. I managed to fix it. Now only problem is the sum of input user doesn't add up correctly. And there is no item sold. Here's my code now
//CIS 226 Assignment 4
//Jeff Chung - September 27, 2010
import java.util.Scanner;

public class Assign4
{
public static void sales()
{
Scanner input = new Scanner( System.in );

double total;
double itemCounter;
double price;
double earnings;
double commission;

total = 0;
itemCounter = 0;
earnings = 0;
commission = 0;

System.out.print( "Enter grade or -1 to quit: " );
price = input.nextInt();

while ( price != -1 )
{
System.out.print( "Enter item value or -1 to quit: " );
price = input.nextInt();
total = price + total;
itemCounter = itemCounter + 1;
commission = total * .09;
earnings = commission + 200;
}

System.out.printf( "\nItems sold: ", itemCounter);
System.out.printf( "\nTotal amount: $%.2f", total );
System.out.printf( "\nCommission: $%.2f", commission);
System.out.printf( "\nEarnings: $%.2f", earnings);

}
public static void main(String[] args) {
new Assign4().sales();

}
}

[Norm]

problem is the sum of input user doesn't add up correctly. And there is no item sold.

Could you copy and paste here the contents of the console window from when you execute the program that shows what it does?

What does the code do with the -1 before it exits the loop?

[nightrise420]

As you can see the value of the item doesnt quite add up correctly. I think when i type -1 to quit, It takes the -1 and sums it up. I can't get the -1 to not add up correctly.

Enter grade or -1 to quit: 1
Enter item value or -1 to quit: 2
Enter item value or -1 to quit: 3
Enter item value or -1 to quit: 4
Enter item value or -1 to quit: -1
Items sold: 4
Total amount: $8.00
Commission: $0.72
Earnings: $200.72

[nightrise420]

So the problem is when the user is asked for the first input before it is sent to the while statement, the input is lost and doesn't add up to the total amount.

[Norm]

What does the code do with the -1 that was entered before it exits the loop?

[nightrise420]

I think it takes -1 as a price input and adds it the total amount.

[nightrise420]

import java.util.Scanner;

public class Assign4
{
public void sales() {
Scanner input = new Scanner( System.in );

int itemCounter;
double total;
double price;
double earnings;
double commission;

total = 0;
itemCounter = 0;
earnings = 0;
commission = 0;

System.out.print( "Enter item value or -1 to quit: " );
price = input.nextInt();
total = price + total;

while ( price != -1 )
{
System.out.print( "Enter item value or -1 to quit: " );
price = input.nextInt();
total = price + total;
itemCounter = itemCounter + 1;
commission = total * .09;
earnings = commission + 200;
}
if ( itemCounter != 0)
{
System.out.printf( "Items sold: %d\n", itemCounter );
System.out.printf( "Total amount: $%.2f\n", total );
System.out.printf( "Commission: $%.2f\n", commission);
System.out.printf( "Earnings: $%.2f\n", earnings);
}
}

public static void main(String[] args) {
new Assign4().sales(); }
}

[Norm]

Does that account for your problem?
You need to test for the -1 and exit the loop before you use it as data.

[nightrise420]

Yes precisely. Now if i can only find out how to write it haha

[Norm]

One way out of a loop is to use a break statement.
Another is to structure the loop so you ask for the value at the end of the loop just before the loop will test it to see if its to continue.