如何将javascript值发送到php并将其显示在重定向页面中

var value = "Hello PHP!";
var xhr = new XMLHttpRequest();
xhr.open("POST", "example.php", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    // 请求成功后的处理逻辑
    window.location.href = "redirect.php";
  }
};
xhr.send("data=" + encodeURIComponent(value));

$data = $_POST['data'];
// 对数据进行处理，例如存储到数据库或进行其他操作

header("Location: display.php?data=" . urlencode($data));
exit();

$data = $_GET['data'];
echo $data;