_isnan
Visual Studio 2010
Checks a given double-precision floating-point value for not a number (NAN).
int _isnan( double x );
The _isnan function tests a given double-precision floating-point value x, returning a nonzero value if x is a not a number (NAN). A NAN is generated when the result of a floating-point operation cannot be represented in Institute of Electrical and Electronics Engineers (IEEE) format. For information about how a NAN is represented for output, see printf.
Routine | Required header |
|---|---|
_isnan | <float.h> |
For more compatibility information, see Compatibility in the Introduction.
Libraries
All versions of the C run-time libraries.
