Equality with Double.NaN

c# equality nan

Chris Cudmore · Feb 17, 2009 · Viewed 17.8k times · Source

I have the following code...

if (Price_Foreign != Double.NaN)
{
   output.Append(spacer);
   output.Append(String.Format("{0,-10:C} USD",Price_Foreign));
}

Which outputs:

NaN USD

What gives?

I'm using Double.NaN to indicate that the value doesn't exist, and shouldn't be output.

Answer

Perhaps you are looking for the IsNaN static function?

Try something like this:

if (!Double.IsNaN(Price_Foreign))
{
   output.Append(spacer);
   output.Append(String.Format("{0,-10:C} USD",Price_Foreign));
}