What string should I pass to java.lang.Long.parseLong() to return a NaN?

I unfortunately cant use expressions like Long.Nan as the string is actually a return value from a different C module. Is there a string开发者_开发问答 I can pass to parseLong() to return an NaN ?

There is no Long.NaN -- you are confused.

For Double.NaN, how about this:

public double myParseDouble(String s)
{
   double result;
   try
   {
      result = Double.parseDouble(s);
   }
   catch (NumberFormatException nfe)
   {
      result = Double.NaN;
   }
   return result;
}

(edit: and the obvious approach is to pass in any string that is an invalid double, e.g. the empty string or NaN)

There is no such thing as Long.NaN, which makes sense when you consider that every bit pattern within long represents a valid integer within the range of [Long.MIN_VALUE, Long.MAX_VALUE].

You might consider trying to get the bit pattern of Double.NaN instead.

Long.Nan? That doesn't exist in Java. You only have Long.MIN_VALUE and Long.MAX_VALUE

"Nan" as argument to Double.parseDouble(String) gives Double.NaN as value if that is what you want.

java.lang.Long represent 64-bit signed integral value, while NaN is introduced only in floating-point computations. That being said there is no special string return Long NaN, but you can for instance use:

double notANumber = java.lang.Double.NaN;

Java only has a concept of NaN for floating point datatypes, not integer ones such as Long.