nan, nanf, nanl
Returns a quiet NaN value.
Syntax
double nan( const char* input );
float nanf( const char* input );
long double nanl( const char* input );
Parameters
input
A string value.
Return value
The nan functions return a quiet NaN value.
Remarks
The nan functions return a floating-point value that corresponds to a quiet (non-signalling) NaN. The input value is ignored. For information about how a NaN is represented for output, see printf, _printf_l, wprintf, _wprintf_l.
By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.
Requirements
| Function | C header | C++ header |
|---|---|---|
nan, nanf, nanl |
<math.h> | <cmath> or <math.h> |
See also
Math and floating-point support
fpclassify
_fpclass, _fpclassf
isfinite, _finite, _finitef
isinf
isnan, _isnan, _isnanf
isnormal