Returns the status word containing information about the floating-point class.
int _fpclass( 
   double x 
);
Parameters
- x
 Double-precision floating-point value.
Return Value
_fpclass returns an integer value that indicates the floating-point class of its argument x*.* The status word might have one of the following values, defined in Float.h.
| Value | Description | 
|---|---|
| _FPCLASS_SNAN | Signaling NaN | 
| _FPCLASS_QNAN | Quiet NaN | 
| _FPCLASS_NINF | Negative infinity ( –INF) | 
| _FPCLASS_NN | Negative normalized non-zero | 
| _FPCLASS_ND | Negative denormalized | 
| _FPCLASS_NZ | Negative zero ( – 0) | 
| _FPCLASS_PZ | Positive 0 (+0) | 
| _FPCLASS_PD | Positive denormalized | 
| _FPCLASS_PN | Positive normalized non-zero | 
| _FPCLASS_PINF | Positive infinity (+INF) | 
Requirements
| Function | Required header | 
|---|---|
| _fpclass | <float.h> | 
For more compatibility information, see Compatibility in the Introduction.