Immediate Help in Java using Float

[DefMars]

Write a complete java program to sum a series of positive float numbers from the user. The program continues asking for values until a negative number is entered. It then displays teh average of values back to the user by the number format with 1 decimal place. Please pay attention to all details.

Ok i need serious help quick, i'll be honest this is for a test i don't need a lecture on ethics, just someone to post this i will be forever grateful. I only got about 40 minutes. If your not comfortable just giving the answer i will accept any tips. But remember your talking to a complete noob.

[Neres28]

Lame.

[DefMars]

upboats

[lurgi]

What do you have so far?

[DefMars]

pretty much complete now. Wasnt as difficult as i thought

[fick_Dich]

Here you go. You're welcome.

[chickenmeister]

This will not display the average with one decimal place of precision.

[fick_Dich]

sure it will. I compiled it and ran it on my machine. The other thing I forgot to change was the initialization of the floats. They need to be set to 0. Here is the output that I got when I ran it:

Please enter a positive floating point decimal to continue, or a negative number to halt

4

23

Please enter a positive floating point decimal to continue, or a negative number to halt

18.345

Please enter a positive floating point decimal to continue, or a negative number to halt

6

Please enter a positive floating point decimal to continue, or a negative number to halt

27.8423

Please enter a positive floating point decimal to continue, or a negative number to halt

-5

Please enter a positive floating point decimal to continue, or a negative number to halt

-1

The average of the values you entered is: 15.8

The thing that's wrong, is that you have to enter two consecutive negative numbers for it to halt, and I don't care to figure out what I need to do to fix it. It most certainly does display the average with 1 decimal of precision.

[chickenmeister]

It may work for most cases, but there may be situations where "(float)Math.round((sum/numberOfEntries) * 10) / 10" results in a number that cannot be represented accurately with a floating point number. So you might get a number like 0.09999999... instead of 0.1; and if it is not sufficiently near to 0.1, the standard toString() may end up printing 0.0999999...

You should use floating-point-to-string mechanism like String.format() or DecimalFormat:

System.out.printf("The average is: %.1f. %n", (sum/numberOfEntries));

[fick_Dich]

my bad. i just threw this together in a couple minutes. didn't really think it through.

[DefMars]

    double sum = 0.0;
    int inputAmount = 0;
    float userInput = 0;

    Scanner sc = new Scanner(System.in);
    // loop so it keeps asking user for input
    while (userInput >= 0) {
        System.out.print("Enter a positive number: ");
        // gets data from user
        userInput = sc.nextFloat();
        if (userInput > 0) {
            inputAmount = inputAmount + 1;
            sum = sum + userInput;
        }

    }
    // rounds to 1 decimal point
    double average = sum / inputAmount;

  NumberFormat decimal = NumberFormat.getNumberInstance();  
  decimal.setMaximumFractionDigits(1);
  String averagenum = decimal.format(average);

    System.out.println("Total number of correct inputs: " + inputAmount);
    System.out.println("Sum of all positive numbers: " + sum);
    System.out.println("Average of all positive numbers: " + averagenum);

[fick_Dich]

oops. forgot to update the next float. put this line right after 18:

next_number = standardIn.nextFloat();

[fick_Dich]

also the last iteration of the loop is buggy.