Get response from PHP file using AJAX

Solution 1:

<?php echo 'apple'; ?> is pretty much literally all you need on the server.

as for the JS side, the output of the server-side script is passed as a parameter to the success handler function, so you'd have

success: function(data) {
   alert(data); // apple
}

Solution 2:

The good practice is to use like this:

$.ajax({
    type: "POST",
    url: "/ajax/request.html",
    data: {action: 'test'},
    dataType:'JSON', 
    success: function(response){
        console.log(response.blablabla);
        // put on console what server sent back...
    }
});

and the php part is:

<?php
    if(isset($_POST['action']) && !empty($_POST['action'])) {
        echo json_encode(array("blablabla"=>$variable));
    }
?>