如何使用Javascript (Ajax)将表单数据发布到外部PHP文件？

<form id="myForm">
  <input type="text" id="name" name="name" placeholder="姓名">
  <input type="email" id="email" name="email" placeholder="邮箱">
  <input type="submit" value="提交">
</form>

var form = document.getElementById("myForm");
form.addEventListener("submit", function(event) {
  event.preventDefault(); // 阻止表单默认提交行为

  var name = document.getElementById("name").value;
  var email = document.getElementById("email").value;

  var xhr = new XMLHttpRequest();
  xhr.open("POST", "external.php", true);
  xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

  // 将表单数据作为参数发送
  var data = "name=" + encodeURIComponent(name) + "&email=" + encodeURIComponent(email);
  
  xhr.onreadystatechange = function() {
    if (xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
      // 请求成功后的处理逻辑
      console.log(xhr.responseText);
    }
  };

  xhr.send(data);
});

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

// 对表单数据进行处理，如存储到数据库等

// 返回响应
echo "表单数据已成功接收并处理";
?>