php 科学技术法

function sctonum($num, $double = 2)
{
    if (false !== stripos($num, "e")) {
        $a = explode("e", strtolower($num));
        $b = bcmul($a[0], bcpow(10, $a[1], $double), $double);
        return $b;
    } else {
        return $num;
    }
}