C/math.h/logb

logb: returns the exponent of num as a floating-point integer value

<source lang="cpp">

//Declaration: float logbf(float num);

              double logb(double num); 
              long double logbl(long double num);  

   
 

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

/* 1.000000 0.000000 2.000000 1.000000 3.000000 1.000000 4.000000 2.000000 5.000000 2.000000 6.000000 2.000000 7.000000 2.000000 8.000000 3.000000 9.000000 3.000000 10.000000 3.000000

• /

      </source>