NAME

isnan - test for a NaN

 SYNOPSIS

#include <math.h>

int isnan(double x);

 DESCRIPTION

The isnan() function tests whether x is NaN.

On systems not supporting NaN values, isnan() always returns 0.

 RETURN VALUE

The isnan() function returns non-zero if x is NaN. Otherwise, 0 is returned.

 ERRORS

No errors are defined.

 EXAMPLES

None.

 APPLICATION USAGE

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

<math.h>.