Getting num_rows from xPDO

$q = "SELECT * FROM modx_site_content WHERE parent='9' AND deleted!='1' AND published='1' ORDER BY menuindex ASC";
$query = new xPDOCriteria($modx, $q); 
if ($query->stmt && $query->stmt->execute()){
while($row = $query->stmt->fetch(PDO::FETCH_ASSOC)) {
echo $row['pagetitle'];
}
}

$modx->getCount('modResource', $query);

$query->stmt->rowCount();

<?php
// use the API to build the query
$q = array(
    'parent' => 9,
    'deleted' => false,
    'published' => true
);
$query = $modx->newQuery('modResource', $q);
$query->sortby('menuindex', 'ASC');

// get the distinct modResource rows that would be selected by this query
// NOTE: this is typically more useful with limit() usage
$numRows = $modx->getCount('modResource', $query);

// you can use xPDO::getCollection() or xPDO::getIterator() here
// to fetch the rows as objects, take advantage of caching, etc.
$iterator = $modx->getIterator('modResource', $query);
foreach ($iterator as $resource) {
    echo $resource->get('pagetitle');
}