PHP的两个科学计数法转换为字符串的方法

public function NumToStr($num) {
        if (stripos($num, ‘e‘) === false)
            return $num;
        $num = trim(preg_replace(‘/[=\‘"]/‘, ‘‘, $num, 1), ‘"‘); //出现科学计数法，还原成字符串
        $result = "";
        while ($num > 0) {
            $v = $num - floor($num / 10) * 10;
            $num = floor($num / 10);
            $result = $v . $result;
        }
        return $result;
    }

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