ajax json decode returning undefined not data - php

Question

I'm trying to pull json data via ajax from a PHP script, but it is not working.
while ($row = mysql_fetch_array($result)) {
$response = array(
'hello' => $row['name']
);
$responses[] = $response;
}
echo json_encode($responses);
Then I use this JavaScript
$('.clickme').click(function() {
$.ajax({
url: 'http://example.com/testFixGet.php?department=1',
dataType: 'json',
data: 'manufacturer=alpine,kicker',
success: function(json) {
alert(json['hello']);
$('.result_new').html(json);
}
});
});
The dialog presents: 'Undefined'
But, if I actually load the php page the data is json decoded and it looks like this:
[{"hello":"Rand McNally Soft Case for Most 5\" GPS"}]

Answer 1

You'll notice your JSON payload contains an array with one object element. Try
alert(json[0]['hello']);
Also, getJSON() is much more concise
$('.clickme').click(function() {
$.getJSON('http://example.com/testFixGet.php', {
department: 1,
manufacturer: 'alpine,kicker'
}, function(json) {
// loop over results
for (var i = 0; i < json.length; i++) {
var response = json[i];
console.log(response);
}
});
});

Answer 2

Try this:
$('.clickme').click(function() {
$.getJSON('testFixGet.php', { manufacturer: "alpine,kicker", department: "1" }, function(json) {
alert(json[0].hello);
$('.result_new').html(json);
} );
}

Answer 3

Are you setting the content type?
header('Content-type: application/json');
ANd by the way
[{"hello":"Rand McNally Soft Case for Most 5\" GPS"}]
it is an array so it would be
alert(json[0]["hello"]);
To loop
var bar = [{"a":"1"},{"a":"2"},{"a":"3"}]
$.each( bar, function(i, jObj){
alert( jObj.a );
});