C Tutorial/math.h/log2

log2

Item Value Header file math.h Declaration float log2f(float num);double log2(double num);long double log2l(long double num); Return returns the base 2 logarithm for num.

<source lang="cpp">#include <math.h>

 #include <stdio.h>
 int main(void)
 {
   double val = 1.0;
   do {
     printf("%f %f\n", val, log2(val));
     val++;
   } while (val<11.0);
   return 0;
 }</source>