IsNan in lens c

Question

There is a function like isNan (a Javascript example) for Objective C ?. I just noticed that this code causes Nan% to display, so I need to determine the value of Nan, so I can change it to 0

     [portefeuillePercentWaarde setText: [NSString stringWithFormat: @ "%. 2f %%", verschilPrencentage]];

Answer 1

Try to add

#include <math.h> 

and then using the standard isnan() function for testing.

You can also use the "trick" that NaN is not equal to anyone, including yourself:

 double x; // do some operation here x = doSomething(); if (x != x) printf("%g is probably NaN, it not equal to itself\n", x);