PHP实现将科学计数法转换为原始数字字符串的方

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;
}