Convert XML string to JSON string, formatted or not.

xml_to_json.php

<?php
function xml_to_json($xml, $formatted=TRUE) {
    $options = (bool)$formatted ? JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE : 0;
    return json_encode(simplexml_load_string($xml), $options);
}

xml_to_jsonTest.php

<?php
$xml = '<Nodes><Node id="1">Content 1</Node><Node id="2">Content 2</Node></Nodes>';
echo xml_to_json($xml);

/*
{
    "Node": [
        "Content 1",
        "Content 2"
    ]
}
*/