How to put the ajax response/result into variable php

You can't PHP is executed on server and Ajax from the client so you cannot assign PHP variable an ajax response. Once a PHP is rendered on the client side it is just HTML no PHP code.

 function random_no(){
 $.ajax({
 url: "test.php",
 success: function(result){
 var result_val=result;
 alert(result); 
 }
 });
 }

As @dev answered , you need to execute server and client code differently ! I answered here for your need variable only .But in developing website, should not use javascript in php tag <?php ?>

ajax.php

<div id="random_no_container">
 <?php
 if(isset($_GET['variable'])) {
 $variable = $_GET['variable'];
 echo $variable;
 } else {
 echo "<script>sessionStorage.setItem('stopped',0);</script>";
 }
 ?>
</div>
<script>
var stopped = sessionStorage.getItem("stopped");
if(stopped == 0) {
 random_no();
}
function random_no(){
 $.ajax({
 url: "test.php",
 success: function(result){
 sessionStorage.setItem("stopped",1);
 //$("#random_no_container").html(result);//the result was displayed on this div
 location.href = "ajax.php?variable="+result;
 }
 });
}
</script>

• javascript
• php
• jquery
• json
• ajax