How to return PHP variables on success AJAX/jQuery POST

Question

How do I use AJAX to return a variable in PHP? I am currently using echo in my controller to display a price on dropdown .change in a div called pr

Answer 1

if u are returning only single value from php respone to ajax then u can set it hidden feild using val method

$("#hidden_fld").val(return_val); 

Answer 2

Well.. One option would be to return a JSON object. To create a JSON object in PHP, you start with an array of values and you execute json_encode($arr). This will return a JSON string.

$arr = array(
  'stack'=>'overflow',
  'key'=>'value'
);
echo json_encode($arr);

{"stack":"overflow","key":"value"}

Now in your jQuery, you'll have to tell your $.ajax call that you are expecting some JSON return values, so you specify another parameter - dataType : 'json'. Now your returned values in the success function will be a normal JavaScript object.

$.ajax({
  type: "POST",
  url: "...",
  data: query,
  dataType: 'json',
  success: function(data){
    console.log(data.stack); // overflow
    console.log(data.key);   // value
  }
});

Answer 3

echo json_encode($RESPONDE);
exit(); 

The exit is not to display other things except answer. RESPONDE is good to be array or object. You can access it at

success: function(data)
             { data }

data is the responde array or whatever you echo.. For example...

echo json_encode(array('some_key'=>'yesss')); exit();

at jquery

success: function(data){ alert(data.some_key); }