将javascript变量传递给新的php页面

var myVariable = "Hello";
window.location.href = "newpage.php?variable=" + encodeURIComponent(myVariable);

$variable = $_GET['variable'];

var myVariable = "Hello";
document.getElementById("hiddenField").value = myVariable;
document.getElementById("myForm").submit();

$variable = $_POST['hiddenField'];

var myVariable = "Hello";
var xhr = new XMLHttpRequest();
xhr.open("POST", "newpage.php", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    console.log("Value sent successfully");
  }
};
xhr.send("variable=" + encodeURIComponent(myVariable));

$variable = $_POST['variable'];