指定在未绑定表单中填写必填字段的方法

<form id="myForm" action="submit.php" method="post">
  <input type="text" id="name" required>
  <input type="email" id="email" required>
  <button type="submit">提交</button>
</form>

<script>
  document.getElementById("myForm").addEventListener("submit", function(event) {
    var name = document.getElementById("name").value;
    var email = document.getElementById("email").value;

    if (name === "" || email === "") {
      alert("请填写必填字段");
      event.preventDefault();
    }
  });
</script>

<?php
$name = $_POST['name'];
$email = $_POST['email'];

if ($name === "" || $email === "") {
  echo "请填写必填字段";
  exit;
}

// 其他处理逻辑
?>