I'm creating the JSON string in PHP, and using AJAX to fetch it.

```
<?php 
// for loop {
    $contacts[] = array(
        'firstname' => $contact->getFname(),
        'lastname' => $contact->getLname(),
        'address' => $contact->getAddress(),
        'city' => $contact->getCity(),
        'postcode' => $contact->getPostcode()
    ); 
// } end for loop

$arr = array('success' => 'yes', 'con' => $contacts);
echo json_encode($arr);
exit;
?>

```

I am not able to iterate a JSON string in Javascript. I have tried using the `for loop`, but I'm unable to get the results

```
for(var i = 0; i < data.con.length; i++) {
    alert(d[i]);
}

```

I want to iterate through each con array in Ajax success function. My code is not working.