我有以下代码，检查是否设置了所有变量，只有当isset（）的所有参数都设置好时，才会返回true
if (isset($_POST['FirstName'], $_POST['Surname'],
$_POST['Telephone'], $_POST['email'], $_POST['PickupPoint'],
$_POST['Destination'], $_POST['StartDate'],
$_POST['NumberofPassengers'])) {
"if all fields have a POST value then send email"
else{
echo "Please fill in all fields.";
}
然而，即使例如PickupPoint和Destination没有填写，电子邮件也会被发送。
这里的问题是空白字段仍然被视为已设置。您还需要使用例如$_POST['PickupPoint'] !== '' 检查它是否为空
完整示例：
if (isset($_POST['FirstName'], $_POST['Surname'],
$_POST['Telephone'], $_POST['email'], $_POST['PickupPoint'],
$_POST['Destination'], $_POST['StartDate'],
$_POST['NumberofPassengers']) && $_POST['PickupPoint'] !== '' && $_POST['Destination'] !== '') { ...
尽管我建议检查所有字段