带有下拉菜单的PHP联系人表单，用于更改电子邮件

我正在制作一份带有下拉菜单的联系表，以选择给特定医生的电子邮件地址。我是从一个模板工作，我没有太多的PHP经验。当我将表单上传到服务器时，我得到了“警告：数组_key_exists（）的参数计数错误”，我无法确定问题所在

<link href="css/contactform.css" rel="stylesheet" type="text/css" />
<?php

// Set email variables
$email_to = array('phys1' => 'phys1@xxxxxx.xxx', 'phys2' => 'phys2@xxxxxx.xxx');
if(array_key_exists($_POST['dropdown']))
{
$recipient = $emails[$_POST['dropdown']];
//send email to $recipient
}

$email_subject = 'Form submission';

// Set required fields
$required_fields = array('fullname','email','comment');

// set error messages
$error_messages = array(
'fullname' => 'Please enter a Name to proceed.',
'email' => 'Please enter a valid Email Address to continue.',
'comment' => 'Please enter your Message to continue.'
);

// Set form status
$form_complete = FALSE;

// configure validation array
$validation = array();

// check form submittal
if(!empty($_POST)) {
// Sanitise POST array
foreach($_POST as $key => $value) $_POST[$key] = remove_email_injection(trim($value));

// Loop into required fields and make sure they match our needs
foreach($required_fields as $field) {       
    // the field has been submitted?
    if(!array_key_exists($field, $_POST)) array_push($validation, $field);

    // check there is information in the field?
    if($_POST[$field] == '') array_push($validation, $field);

    // validate the email address supplied
    if($field == 'email') if(!validate_email_address($_POST[$field])) array_push($validation, $field);
    }

// basic validation result
if(count($validation) == 0) {
    // Prepare our content string
    $email_content = 'New Website Comment: ' . "\n\n";

    // simple email content
    foreach($_POST as $key => $value) {
        if($key != 'submit') $email_content .= $key . ': ' . $value . "\n";
    }

    // if validation passed ok then send the email
    mail($email_to, $email_subject, $email_content);

    // Update form switch
    $form_complete = TRUE;
}
}

function validate_email_address($email = FALSE) {
return (preg_match('/^[^@\s]+@([-a-z0-9]+\.)+[a-z]{2,}$/i', $email))? TRUE : FALSE;
}

function remove_email_injection($field = FALSE) {
   return (str_ireplace(array("\r", "\n", "%0a", "%0d", "Content-Type:", "bcc:","to:","cc:"), '', $field));
}

?>

<script type="text/javascript">
    var nameError = '<?php echo $error_messages['fullname']; ?>';
    var emailError = '<?php echo $error_messages['email']; ?>';
    var commentError = '<?php echo $error_messages['comment']; ?>';
</script>

</head>
<div id="formWrap">
<div id="form">
<?php if($form_complete === FALSE): ?>
<form action="/contact.php" method="post" id="comments_form">
    <div class="row">
    <div class="label">Name</div>
    <div class="input">
    <input type="text" id="fullname" class="detail" name="fullname" value="<?php echo isset($_POST['fullname'])? $_POST['fullname'] : ''; ?>" /><?php if(in_array('fullname', $validation)): ?><span class="error"><?php echo $error_messages['fullname']; ?></span><?php endif; ?>
    </div>
    <div class="context"></div>

    <div class="row">
    <div class="label">Your E-mail</div>
    <div class="input"><input type="text" id="email" class="detail" name="email" value="
<?php echo isset($_POST['email'])? $_POST['email'] : ''; ?>" />
<?php if(in_array('email', $validation)): ?><span class="error"><?php echo $error_messages['email']; ?></span><?php endif; ?>
    </div>
    <div class="context"></div>

    <div class="row">
    <div class="label">Select Physician</div>
    <div class="input"><select name='dropdown' >
<option value=''>

    --Select--</option>
<option value='phys1'>

    phys1</option>
<option value='phys2'>

    phys2</option>
<option value='phys3'>

    phys3</option>
</select>       </div>
    <div class="context"></div>


    <div class="row">
    <div class="label">

     Your Message</div>
    <div class="input">
    <textarea id="comment" name="comment" class="mess"><?php echo isset($_POST['comment'])? $_POST['comment'] : ''; ?></textarea><?php if(in_array('comment', $validation)): ?><span class="error"><?php echo $error_messages['comment']; ?></span><?php endif; ?>
    </div>
    </div>  
    <div class="submit"></div>
    <input type="submit" id="submit" name="submit" value="Send Message" />
</div>
</form>
<?php else: ?>
<p>

    Thank you for your message!</p>
 <?php endif; ?>
</div>
</div>
</div>
</div>
</div>
</div>  
</div>  
</body>
</html>

var nameError=''；
var-emailError=''；
var commentError=''；
名称
尝试将
array\u key\u exists
替换为
isset
，看看是否适合您

if(isset($_POST['dropdown']))
{
    $recipient = $emails[$_POST['dropdown']];
    //send email to $recipient
}

如果查看的文档，您会注意到该函数包含两个参数。一个键（数组键）和一个数组（要搜索相关数组键/索引的数组）

您的代码：

if(array_key_exists($_POST['dropdown']))

这就是问题所在。你可能是说：

if(array_key_exists($_POST['dropdown'], $emails))

如果（array\u key\u exists（$\u POST['dropdown']））
-它不需要两个参数吗？array\u key\u exists通常用于将用户输入列为白名单。将其更改为isset（）可能会引入漏洞。嗯。。。不。它们的工作原理是相同的，唯一的区别是
isset
将返回
false
，如果键存在，但其值为
NULL
（没有
$\u POST
会有），如果$\u POST['dropdown']作为变量存在，isset（）将返回TRUE。如果在上面的代码中引入了isset（），您仍然无法确定$u POST['dropdown']的值是否代表$emails数组中的有效键<代码>isset（$emails[$\u POST['dropdown']]）

可以工作，而不是

isset（$\u POST['dropdown']）