使用 PHP 函数创建交互式 Web 表单

<form action="process.php" method="post">
  <label for="name">姓名：</label>
  <input type="text" id="name" name="name" required>

  <label for="email">邮箱：</label>
  <input type="email" id="email" name="email" required>

  <input type="submit" value="提交">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $name = $_POST['name'];
  $email = $_POST['email'];

  // 在这里处理表单数据
}
?>

<?php
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
  // 有效的电子邮件地址
} else {
  // 无效的电子邮件地址
}
?>

<?php
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
  echo "<p>无效的电子邮件地址</p>";
}
?>

<!-- form.php -->
<form action="process.php" method="post">
  <label for="username">用户名：</label>
  <input type="text" id="username" name="username" required>

  <label for="password">密码：</label>
  <input type="password" id="password" name="password" required>

  <input type="submit" value="注册">
</form>

<!-- process.php -->
<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  // 获取表单数据
  $username = $_POST['username'];
  $password = $_POST['password'];

  // 验证表单输入
  if (!preg_match('/^[a-zA-Z0-9]+$/', $username)) {
    echo "<p>无效的用户名</p>";
  } else if (!preg_match('/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)[a-zA-Z\d]{8,}$/', $password)) {
    echo "<p>无效的密码</p>";
  } else {
    // 密码散列和插入数据库
    $hashedPassword = password_hash($password, PASSWORD_DEFAULT);
    $query = "INSERT INTO users (username, password) VALUES (?, ?)";
    $stmt = $conn->prepare($query);
    $stmt->bind_param('ss', $username, $hashedPassword);
    $stmt->execute();

    echo "<p>注册成功！</p>";
  }
}
?>