Question

I have this function I am writing.

  const int ProgressBarLength = 230;
  foreach (TransactionDetail item in list)
  {
      var itemProgress =
        ((ProgressBarLength/item.PurchasesRequired) *
        Convert.ToInt32(item.TransactionAmount));

      item.ProgressBar = itemProgress > ProgressBarLength ? ProgressBarLength : itemProgress;
  }

Now I have 2 TransactionDetails in my loop.

If item.PurchasesRequired = 500 and TransactionAmount = 199.0 the resulting value is 0. However, if item.PurchasesRequired = 5 and TransactionAmount = 94.0 it returns a valid result.

What am I doing wrong?

Answer 1

It looks like you’re performing integer division.

230 / 500 is zero in integer division, whereas 230 / 5 is 46.

You can force floating-point division by casting PurchasesRequired to a double. 230 / 500 is 0.46 in floating-point division, as you’d expect.

const int ProgressBarLength = 230;
foreach (TransactionDetail item in list)
{
    var itemProgress = ((ProgressBarLength / (double)item.PurchasesRequired)
                        * Convert.ToInt32(item.TransactionAmount));
    item.ProgressBar = Math.Min((int)itemProgress, ProgressBarLength);
}