log() - math.h

The C library function double log(double x) returns the natural logarithm (base-e logarithm) of x.

Syntax

double log(double x)

Example

#include <stdio.h>
#include <math.h>

int main ()
{
   double x, ret;
   x = 2.7;

   /* finding log(2.7) */
   ret = log(x);
   printf("log(%lf) = %lf", x, ret);
   
   return(0);
}

Output / Return Value

log(2.700000) = 0.993252

Limitations

Alternatives / See Also

Reference