Question

I have a double[] on which a LINQ operation is being performed:

MD = MD.Select(n => n * 100 / MD.Sum()).ToArray();

In some cases, all elements of MD are 0 and then Sum is also zero. Then 0 * 100 = 0 / 0, but it is not giving a divide-by-zero exception or any exception. Why is this so?

Answer 1

Try this:

double x = 0.0;
double y = 1.0;
double z = y / x;

That won’t throw an exception either: it’ll leave z as positive infinity. There’s nothing LINQ-specific here – it’s just IEEE-754 floating point arithmetic behaviour.

In your case, you’re dividing zero by zero, so you end up with not-a-number.