Thread: Average and counting problem (sorta)

So, my code compiles fine and everything with a do-while loop, but when it counts how many numbers there are and averages them all, the count adds the 0 and the average also includes the 0 which I don't want it to. Please help and thank you in advance!

import java.util.Scanner;
 
//Counts pos #, neg #, and averages them.
public class Avg_Pos_Neg_Num {
	public static void main(String[] args) {
 
//what integers?
		int numbers = 0;
		int total = 0;
		int positive = 0;
		int negative = 0;
		int sum = 0;
		double avg = 0.0;
 
		Scanner input = new Scanner(System.in);
 
//Tell user to enter pos and neg numbers with spaces.
//while loop
		do { 
			System.out.print("Enter any positive or negative number (0 ends program): ");
			numbers = input.nextInt();
 
			total++;
			if (numbers > 0) {positive++;}
			else if (numbers < 0) {negative++;}
		}
		while (numbers != 0);
 
//Compute
		sum = (positive + negative);
		avg = ((double)sum / total);
 
//Output
		System.out.println("The number of positive numbers is " + positive);
		System.out.println("The number of negative numbers is " + negative);
		System.out.println("There are " + total + " numbers");
		System.out.println("The average of the numbers is " + avg);
 
			}
		}

What do you mean to add code to test for the 0 with an if statement?

Thanks for that. I just added

 else if (numbers == 0) {total--;}

into the nested if's and it counted right, but now, I found out my averages, even if I go put a negative into the equation, the average won't go negative and just stay positive. I also put

 int negative = -0;

if that helps.

Can you give an example run to show what you mean? Copy the run from the console output and post it. Include a description of how the run is different than you expect.

Enter any positive or negative number (0 ends program): -5
Enter any positive or negative number (0 ends program): 2
Enter any positive or negative number (0 ends program): -10
Enter any positive or negative number (0 ends program): 3
Enter any positive or negative number (0 ends program): 0
The number of positive numbers is 2
The number of negative numbers is 2
There are 4 numbers
The average of the numbers is 1.0

So, I guess the program really isn't doing the average right either. Every time I compile the program, it counts all the numbers correctly, but it won't average the numbers because in this result, I should be getting -2.5 as the average, but it's only 1.0 and doesn't turn into a negative.

Check your formula for 'sum.' What is it currently the sum of? Is that 'sum' going to give you the desired average?

Hint: The formula for 'sum' (whatever it is) should be inside the do/while loop.

I changed my loop and compute to this

//do-while loop w/ sum inside
		do { 
			System.out.print("Enter any positive or negative number (0 ends program): ");
			numbers = input.nextInt();
 
			total++;
			if (numbers > 0) {positive++;}
			else if (numbers < 0) {negative++;}
			else if (numbers == 0) {total--;}
			sum = (numbers);
		}
		while (numbers != 0);
 
//Compute 
		avg = (sum / total);

but now it turns out to 0.0 for the average. I think it might be because of the 0, but when I tried to output the 'sum' as well, that also came out to 0.0 too.

'sum' needs to sum all numbers entered by the user, not just the last number entered, which is what your code currently does. That's why it's zero.

In words, each time through the loop, sum = previousSum + numberEntered

What is previousSum?

Thanks. I did this instead:

sum += numbers

and

avg = ((double) sum / total)