mongodb num_rows 相当于 php

我怎样才能得到结果的数量，相当于num_rows(mysqli) 在mongodb?

如果我有

$db->$dbName->find(array("email" => $newemail, "password" => $newpass));

检查符合此条件的结果数量的最佳方法是什么？

在 mysqli 中我会做类似的事情

$sql = "SELECT id FROM table WHERE email='%s' AND password='%s'";
$query = sprintf($sql, $newemail, $newpass);
$result = $conn->query($query);
$rows = $result->num_rows;

像这样，我认为：

$collection = $connection->myDB->myCollection;
$cursor = $collection->find(array("email" => $newemail, "password" => $newpass));
$nResults = $cursor->count();