Question

So, I run this javascript . this code gets the html generated by cart.php

$.ajax({
    type: "GET",
    url: "/cart/cart.php",
    async: false,
    dataType: "html",
    success: function(html){
            $('#cart_content').html(html);          
    }

QUESTION ! how can get the value of a variable in cart.php ?

I would love something like this : $('#cart_content').html($myvar);

Answer 1

Personally, the easiest way is to return json, or simply echo-ing out the data you want returned. If you were to do json, change the dataType to json, and then, on cart.php,
echo json_encode(array('varname'=>$myvar));
In your success function, you will be able to call that variable: $('#cart_content').html(html.varname);

If you choose to go the simple route, on cart.php, just echo the data. Your success function will have it stored as html.