Tests for infinity.
#include <math.h>
int isinf (x)
real-floating x;
The isinf macro determines whether its argument value is an infinity (positive or negative). An argument represented in a format wider than its semantic type is converted to its semantic type. Determination is based on the type of the argument.
Item | Description |
---|---|
x | Specifies the value to be checked. |
The isinf macro returns a nonzero value if its argument has an infinite value.