PHP convert XML to JSON

I am trying to convert xml to json in php. If I do a simple convert using simple xml and json_encode none of the attributes in the xml show.

$xml = simplexml_load_file("states.xml");
echo json_encode($xml);

So I am trying to manually parse it like this.

foreach($xml->children() as $state)
{
    $states[]= array('state' => $state->name); 
}       
echo json_encode($states);

and the output for state is {"state":{"0":"Alabama"}} rather than {"state":"Alabama"}

What am I doing wrong?

XML:

<?xml version="1.0" ?>
<states>
    <state id="AL">     
    <name>Alabama</name>
    </state>
    <state id="AK">
        <name>Alaska</name>
    </state>
</states>

Output:

[{"state":{"0":"Alabama"}},{"state":{"0":"Alaska"}

var dump:

object(SimpleXMLElement)#1 (1) {
["state"]=>
array(2) {
[0]=>
object(SimpleXMLElement)#3 (2) {
  ["@attributes"]=>
  array(1) {
    ["id"]=>
    string(2) "AL"
  }
  ["name"]=>
  string(7) "Alabama"
}
[1]=>
object(SimpleXMLElement)#2 (2) {
  ["@attributes"]=>
  array(1) {
    ["id"]=>
    string(2) "AK"
  }
  ["name"]=>
  string(6) "Alaska"
}
}
}

Answer

I figured it out. json_encode handles objects differently than strings. I cast the object to a string and it works now.

foreach($xml->children() as $state)
{
    $states[]= array('state' => (string)$state->name); 
}       
echo json_encode($states);