Front page | perl.perl5.porters |
Postings from October 2003
On Tue, Oct 07, 2003 at 08:20:00PM +0200, Tels wrote:
> On Tuesday 07 October 2003 20:12, Tels wrote:
>
> This is very wierd:
>
> # perl -MPOSIX -le '$a = (81 ** 3) ** (1/3); print join(" ", $a, int ($a),
> POSIX::floor($a), sprintf("%f",$a), sprintf ("%.0f",$a))'
> 81 80 80 81.000000 81
>
> Why is $a sometimes 81, and sometimes 80? Why does int(81) produce 80?
Because (81 ** 3) ** (1/3) != 81
$ perl -le 'print ((81 ** 3) ** (1/3) != 81)'
1
$ perl -MPOSIX -le '$a = (81 ** 3) ** (1/3); print join(" ", $a, int ($a), POSIX::floor($a), sprintf("%f",$a), sprintf("%.20f",$a), sprintf ("%.0f",$a))'
81 80 80 81.000000 80.99999999999998578915 81
--
Paul Johnson - paul@pjcj.net
http://www.pjcj.net