PHP没有正确地舍入浮动？

Question

我正试图绕过双0.0045。当我打电话给...

echo round($theFloat, 3);

我得到0.004，而不是0.005，这是预期的反应。

以下是代码：

$increase = 1.1;
$previousPrice = round(0.11 / $increase, 2);
$nextPrice = round(0.11 * $increase, 2);
$afterCut = round(0.11 * 0.95, 6);
$willSend = $afterCut - $previousPrice;
echo round($willSend, 3);

Answer 1

试试这个

$increase = 1.1;
$previousPrice = 0.11 / $increase;
$nextPrice = 0.11 * $increase;
$afterCut = round(0.11 * 0.95, 6);
$willSend = $afterCut - $previousPrice;
echo round($willSend, 3);

Answer 2

虽然您拥有的内容，如0.0045，但实际的值约为0.00449999999999999966，因为IEEE 754 floating point values cannot specify exactly that number。 值在舍入到3位时为0.004。