note
moritz
<p>[doc://log] returns a floating-point number, so the results are prone to [http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html|floating-point inaccuracies]:
<code>
$ perl -wE 'printf "%.20f\n", log(125)/log(5)'
3.00000000000000044409
</code>
<p>A safer test is something like this here, which only uses integers:
<code>
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);
</code>
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[http://perl6.org/|Perl 6 - the future is here, just unevenly distributed]
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