php保留两位小数并且四舍五入
$num = 5566.56831; echo sprintf("%.2f", $num);
php保留两位小数并且不四舍五入
$num = 5566.56831; echo sprintf("%.2f",substr(sprintf("%.3f", $num), 0, -2));
php进一法取整
echo ceil(4.2); // 5 echo ceil(9.999); // 10
php舍去法取整
echo floor(4.2); // 4 echo floor(9.999); // 9