Determine NaN(not a number value)

Question

I perform some Calculations with floats, and sometimes I divide a number by zero or even zero by zero. As a result, some values of my output array contain -1.#IND0000 values. After that I need to determine whether the value is "normal" or "NaN". How can I do it with if statement?

score 2 · Accepted Answer · answered Dec 09 '14 at 20:52

2

Try isnan(). That's the one you're looking for.

#include <math.h>

void YourCode() {

    float x = /* some value from your array here */;
    if (isnan(x)) { 
        // ... do stuff ...
    }

}

answered Dec 09 '14 at 20:52

i_am_jorf

53,608
15
131
222

Thanks!For my program turned out isfinite() is more useful, but I was not really specific with my question – Mihon Dec 09 '14 at 20:56
3

C++ is: #include and std::isnan(x) – Dec 09 '14 at 21:14

Determine NaN(not a number value)

1 Answers1