How to determine how many bytes an integer needs?

Question

I\'m looking for the most efficient way to calculate the minimum number of bytes needed to store an integer without losing precision.

e.g.

int: 10 = 1 byte
         


        

Answer 1

You need exactly the log function

nb_bytes = floor(log(x)/log(256))+1 if you use log2, log2(256) == 8 so

floor(log2(x)/8)+1