Question

我一直在颠倒浏览该php表单，但是我没有找到为什么不显示错误消息，并且即使所有字段为空，该表单也会始终发送电子邮件。有我的代码：

<form name="contactform" method="post" action="">
  <input type="text" data-placeholder="<?php echo $name; ?>"name="name">
  <input type="text" data-placeholder="<?php echo $email; ?>"name="email">
  <textarea data-placeholder="<?php echo $message; ?>" name="message" rows="10"></textarea>
  <input type="submit" name="submit" class="btn btn-footer" value="ENVOYER" id="btnContact">
  <p class="text desktop"><?php echo $emailErr; ?></p>
</form>

<?php
  if(isset($_POST['submit'])) {
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $emailErr = "";

    if (!isset($name) || $email=="" || $message=="" ) {
      $emailErr = "All fields are mendatory";
    } else {
      $mailTo = "test@gmail.com";
      mail($mailTo);
      $emailErr = "Email Send";
    }
 }
 ?>

Answer 1

if (empty($name) || empty($email) || empty($message)) 
 {
     $emailErr = "All fields are mendatory";
 }

您可以使用php函数为空或is_null

Answer 2

在这种情况下，

isset()将始终返回true，因为已设置了变量（为空字符串）。要检查变量是否为空，应使用对$email和$message所做的操作：

if ( $name == "" || $email == "" || $message == "" ) {

为演示，您只需运行以下命令即可：

$a = ""
var_dump(!isset($a)); // false
var_dump($a == ""); // true

Answer 3

提交表单后，如果存在字段名称，则isset()将返回true。但是，如果您检查任何字段的空值，则可以使用empty($fieldname)或$fieldname == ""或$fieldname == NULL。

尝试一下：

if(isset($_POST['submit'])) {
  $name = $_POST['name'];
  $email = $_POST['email'];
  $message = $_POST['message'];
  $emailErr = "";

  if (empty($name) || empty($email) || empty($message) ) {
    $emailErr = "All fields are mendatory";
  } else {
    $mailTo = "test@gmail.com";
    mail($mailTo);
    $emailErr = "Email Send";
  }
}

Answer 4

请尝试这个，

我在本地系统中检查了它的工作正常，错误和成功消息，这是根据您的要求

<?php
  if(isset($_POST['submit'])) {
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $emailErr = "";

    if (!isset($name) || $email=="" || $message=="" ) {
      $emailErr = "All fields are mendatory";
    } else {
      $mailTo = "test@gmail.com";
      mail($mailTo);
      $emailErr = "Email Send";
    }
 }
 ?>
 <form name="contactform" method="post" action="">
  <input type="text" data-placeholder="<?php echo $name; ?>"name="name">
  <input type="text" data-placeholder="<?php echo $email; ?>"name="email">
  <textarea data-placeholder="<?php echo $message; ?>" name="message" rows="10"></textarea>
  <input type="submit" name="submit" class="btn btn-footer" value="ENVOYER" id="btnContact">
  <p class="text desktop"><?php echo $emailErr; ?></p>
</form>

PHP表单找不到空字段

4 个答案: