Re: log() and int() problem

[moritz]

in reply to log() and int() problem

log returns a floating-point number, so the results are prone to floating-point inaccuracies:

$ perl -wE 'printf "%.20f\n", log(125)/log(5)'
3.00000000000000044409

A safer test is something like this here, which only uses integers:

use strict;
use warnings;
use 5.010;

sub is_power_of {
    my ($num, $base) = @_;

    while ($num > 1) {
        return 0 if $num % $base != 0;
        $num /= $base;
    }
    return 1;
}

say is_power_of(125, 5);

[Anonymous Monk]

Idly curious why a loop and "/=" are needed. Not questioning but curious. Example?

[Anonymous Monk]

Add  print "$num\n"; and you can see how the loop works