c - How to raise a double value by power of 12?

Question

I have a double which is:

double mydouble = 10;

and I want 10^12, so 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10 * 10. I tried

double newDouble = pow(10, 12);

and it returns me in NSLog: pow=-1.991886

makes not much sense... I think pow isn't my friend right?

Answer 1

try pow(10.0, 12.0). Better yet, #include math.h.

To clarify: If you don't include math.h, the compiler assumes that pow() returns an integer. Including math.h brings in a prototype like

double pow(double, double);

So the compiler can understand how to treat the arguments and the return value.