standard.C.math.log10

log10 is available since version 1.0.

Prototype:

number log10(number n)

Parameters

n
[in] Number whose base-10 logarithm is to be found

Description:

Returns the base-10 logarithm of n if successful. If n is negative or 0, log returns an indefinite, by default.

Return value:

Returns the base-10 logarithm of n if successful. If n is negative or 0, log returns an indefinite, by default.

Example
import standard.C.math

class Main {
     function Main() {
          var x = 9000;
          var y;

          y = log(x);
          echo "log(" + x + ") = " + y + "\n";
          y = log10(x);
          echo "log10(" + x + ") = " + y;
     }
}  

Results 
log(9000) = 9.1049798563183568
log10(9000) = 3.954242467880249