Nullable double NaN comparison in C#

Question

I have 2 nullable doubles, an expected value and an actual value (let\'s call them value and valueExpected). A percentage is found using 100 * (value / valueExpected). Howev

Answer 1

With all Nullable instances, you first check the bool HasValue property, and then you can access the T Value property.

double? d = 0.0;        // Shorthand for Nullable
if (d.HasValue && !Double.IsNaN(d.Value)) {
    double val = d.Value;

    // val is a non-null, non-NaN double.
}