isfinite()

Determine if a number is finite

Synopsis:

```#include <math.h>

int isfinite ( double x );
```

Since:

BlackBerry 10.0.0

Arguments:

x
The number you want to test.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

The isfinite() macro determines if x is finite.

Returns:

True (1)
The value of x is finite.
False (≠ 1)
The value of x is infinity or NAN.

Examples:

```#include <stdio.h>
#include <errno.h>
#include <inttypes.h>
#include <math.h>
#include <fpstatus.h>

int main(int argc, char** argv)
{
double a, b, c, d;

a = 2;
b = -0.5;
c = NAN;
d = 1.0/0.0;
printf("%f is %s \n", a, (isfinite(a)) ? "finite" : "not finite");
printf("%f is %s \n", b, (isfinite(b)) ? "finite" : "not finite");
printf("%f is %s \n", c, (isfinite(c)) ? "finite" : "not finite");
printf("%f is %s \n", d, (isfinite(d)) ? "finite" : "not finite");

return(0);
}
```

produces the output:

```2.000000 is finite
-0.500000 is finite
NAN is not finite
Inf is not finite
```

Classification:

Safety:
Cancellation point No
Interrupt handler No
Signal handler No