顯示-0.3*2 0.6=1.1102230246252E-16 而不是零，誰知道為什麼阿？求教大神
$x = [3, 0, 2];
$tArr = [0.2, 0.3, - 0.3];
$s = 0;
foreach ($x as $k => $e) {
$s = $ e * $tArr[$k];
echo $s . PHP_EOL;
}
