my $y = 1.5;
$y = sprintf "%.0f", $y;
my $x = 2.5;
$x = sprintf "%.0f", $x;
print "$y\n$x\n";

[download]

Still surprised? As pg says above, perl's rounding is unbiased - rather than rounding every .5 up, it always rounds to even. 1.5 and 2.5 both become 2.

Update: This is not documented. What is documented in perlfaq4 is this:

it probably pays not to trust whichever system rounding is being used by Perl, but to instead implement the rounding function you need yourself.

I downloaded 5.6.1 from AS, and as ikegami says below it rounds 1.5 to 2 and 2.5 up to 3. Oh, and this all has nothing to do with the original question ;)

In reply to Re: Rounding error? by bmann
in thread Rounding error? by dracos

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