Question

I don’t understand how the success function works in a $.ajax call with jquery.

for instance

$.ajax({
    type: "POST",
    url: "ajax.php",
    data: "function=1",
    success: function(data,response,jqxhr){
         useReturnData(data /* ??? not sure how to use the data var */ );
    }
};

ajax.php:

 <?php
      if ($_REQUEST['function'] == '1'){
            $string = "this is the data i want to return and use";
      }
 ?>

how do i use that data within the success function? No where seems to explain what the data parameter is, they just seem to use it ambiguously.

another side question, is the data: “function=1” related to the data as a parameter for the success function?

Answer 1

The data variable contains the output of your php file, so if in your php file you do:

echo "<p>success</p>";

data will contain <p>success</p>.

In your example you would change your php file to:

<?php
      if ($_REQUEST['function'] == '1'){
            $string = "this is the data i want to return and use";
      }

      // other stuff...

      echo $string;
 ?>