Question

Could someone please explain to me why my average keeps coming as 0 when I run my program? I have listed the entire code of my project on here and have literally never used arrays before. Also, is the name of this array mData? I tried reading in my book to determine what to look for in these items and have come up with nothing.

public partial class frmMain : Form
{

    private const int mSize = 20;
    private int[] mData = new int[mSize];
    private int mIndex = 0;


    private static void Main()
    {
        frmMain main = new frmMain();
        Application.Run(main);
    }
    private frmMain()
    {
        InitializeComponent();
    }

    private void btnEnter_Click(object sender, EventArgs e)
    {
        int num;
        num = int.Parse(txtInput.Text);

        //store num in the array
        mData[mIndex] = num;
        mIndex = mIndex + 1;

        //check for full array
        if (mIndex == mSize)
        {
            //inform user that array is full
            MessageBox.Show("The array is full.");
            btnEnter.Enabled = false;
        }
    }

    private void btnExit_Click(object sender, EventArgs e)
    {
        Close();
    }

    private void btnDisplay_Click(object sender, EventArgs e)
    {
        int n;

        for (n = 0; n < mIndex; n++)
            listBoxOutput.Items.Add(mData[n]);
    }

    private void btnAverage_Click(object sender, EventArgs e)
    {

        int sum = 0;
        int average = 0;

        if (mIndex == 0)
        {
            //inform user that array is empty
            MessageBox.Show("The array is empty.");
        }

        //add up the values
        for (int i = 0; i < mData.Length; i++)
        {
            sum += mData[i];
        }

        //divide by the number of values
        average = sum / mSize;

        listBoxOutput.Items.Add("The average of the array is: " + average);
    }

}

Answer 1

One problem is that you are using ints. If the final value is a decimal less than 1, the int average will store 0. Changing average to a float will solve this. Also, you should not divide by mSize unless you know the entire array is filled. The user could insert one value, but it would be averaged with 19 0s.