Why the jQuery AJAX. Return value is undefined?

Question

A weird thing is happening when I execute a function that "alerts" data from a json. If I specify, like alert(data.name);, the "Alert" returns "Undefined", but if I just put alert(data);, it returns the object like {"id":"1","name":"Erluan"}

This is the function that receives an id to search in the database

function receiveUser(val){
            $.ajax({
               type:"POST",
               url:"../json/userperm/userGrid.php",
               data: 'iduser='+val,
               datatype:"json",
               success: function(data, string, jqXHR){
                    alert(data.name);
               }
            });
}

And this is the userGrid.php

<?php
include('../../config.php');

$user = mysql_query("SELECT * from hospital_".$_SESSION['template'].".users where id = ".$_POST['iduser']." order by name");

$results = array();

while($row = mysql_fetch_array($user))
{
   $results[] = array(
      'id' => $row['id'],
      'name' => $row['name']
   );
}

$json = json_encode($results);

echo $json;
?>

Thank you.

Since the return datatype is json the OP should not have to use JSON.parse @JonathanNewton — Jay Blanchard, Feb 08 '17 at 16:39
$results is array of array...after json_encode it will be array of objects. So, in JS you need to read it through loop. In current case you can try data[0].name it will work. — Naincy, Feb 08 '17 at 16:39
@JonathanNewton jQuery should already be parsing any JSON that is returned — mhodges, Feb 08 '17 at 16:40
can u share console.log(data); and see my answer change typo of dataType from datatype. JS is caseSensitive. — Naincy, Feb 08 '17 at 16:47
@Erluan could you `console.log(data)` the output and attach it to your question? — Jonathan Newton, Feb 08 '17 at 16:48
@JayBlanchard I'm not sure OP put the exact result see: "it returns the object like" also [see](https://jsfiddle.net/wvto6953/) — Jonathan Newton, Feb 08 '17 at 16:51
@JayBlanchard also worth looking at the correct answer my initial comment was try and convert the string into JSON this would have brought OP to the correct answer sooner. — Jonathan Newton, Feb 08 '17 at 16:58

score 0 · Accepted Answer · edited May 23 '17 at 12:01

0

Returning JSON from a PHP Script

Your php script needs the correct header:

header('Content-Type: application/json');

It seems JQuery is intrepteing the result as the string {"id":"1","name":"Erluan"}, by having the correct header it should then be parsed as JSON.

edited May 23 '17 at 12:01

Community

1
1

answered Feb 08 '17 at 16:52

Andrew Monks

656
4
11

Also on your ajax request it should be "dataType" not "datatype", changing this would of also fixed the issue. – Andrew Monks Feb 08 '17 at 16:58

score 0 · Answer 2 · answered Feb 08 '17 at 18:55

0

Have you tried evaluating the ajax response? If not then try to call eval function and then fetch the values.

 success: function(data, string, jqXHR){
               var res = eval('(' + data+ ')');
                alert(res.name);
           }

answered Feb 08 '17 at 18:55

Priya Singh

66
7

Why the jQuery AJAX. Return value is undefined?

2 Answers2