如何为jquery / ajax发布结果分配值？

Question

I'm posting data to a php page using jquery. I want to then have the response from the page be able to be put into php variables on the original page. I don't want to append a DIV or show the results in the HTML. (This seems to be the only thing people do with post.)

Here's the jquery:

$(document).ready(function () 
{
    $('#drpdown').change(function() 
    {
        drpdownval=$('#drpdown').val();
        $.post("page2.php",{incomingval:drpdownval},function(result))};

    });
});

PHP page2.php:

<?php
$valtoworkwith = $_REQUEST['incomingval'];
......../// do something
?>

I want to then do something on page2.php then send specific values back to the jquery to work with. How? How do I assign them a name or separate them out??

EDIT

My jquery needed a number and not text.

Here's the jquery:

$(document).ready(function () 
{
    $('#drpdown').change(function() 
    {
        drpdownval=$('#drpdown').val();
        $.post("page2.php",{incomingval:drpdownval},function(result){
          if(result != 1){ ///could not put result !="hello" or != hello
          $("#signup").overlay().load();  
          }
        )};
    });
});

Answer 1

Use JSON to get your inter-connectivity going, meaning the data exchange between client and server entirely through AJAX. Here's a link to a StackOverflow answer which goes into detail about how to make that happen, using PHP for the back end:

jQuery AJAX Call to PHP Script with JSON Return

Answer 2

Simply go here, it's as clear as it can get...

https://api.jquery.com/jQuery.ajax/

That's the documentation page for $.ajax, and if you scroll down you will have excellent examples you can start from.

Answer 3

Are you trying to do something like that?

if (!empty($_POST['incomingval'])){
  $valtoworkwith = $_POST['incomingval'];
  //do some stuff
  echo $valtoworkwith;
}

Or if you want to sent back a JSON

<?php

  function doSomeStuff($input) {
    //instead of that do some stuff and return back something that makes sense
    $output = $input;
    //
    return $output;
  }

  if (!empty($_POST['incomingval'])){
    header('Content-Type: application/json');

    $valtoworkwith = $_POST['incomingval'];
    $res = doSomeStuff($valtoworkwith);

    $data = array('incomingval' => $valtoworkwith, 'response' => $res);
    echo json_encode($data);
  }

?>

I hope that helped you because the answer it self was kind of vague.

Tested with postman

The in JS you can do with a promise

$(document).ready(function () 
{
    $('#drpdown').change(function() 
    {
        drpdownval=$('#drpdown').val();

        $.post("page2.php",{incomingval:drpdownval})
        .then(function(data){ //look how awesome the promise looks
        console.log(data.response); //do something with it
        })

    });
});