从 stdClass 对象数组中提取数据

我正在对 Salesforce 进行 api 调用，print_r($response( 返回以下结果

QueryResult Object
(
    [queryLocator] => 
    [done] => 1
    [records] => Array
        (
            [0] => stdClass Object
                (
                    [Id] => 0018000001O5tRgAAJ
                    [Contacts] => stdClass Object
                        (
                            [done] => 1
                            [queryLocator] => 
                            [records] => Array
                                (
                                    [0] => stdClass Object
                                        (
                                            [Id] => 0038000001yxYP3AAM
                                            [Email] => mktest3@gmail.com
                                            [FirstName] => mary
                                            [LastName] => kell
                                        )
                                )
                            [size] => 1
                        )
                    [Name] => mktest3
                )
        )

我可以使用以下 php 脚本从第一个 stdClass Object 数组中挑选出某些数据，但我如何从第三个数组中执行相同的操作？基本上，我正在尝试获取联系人的ID，电子邮件，名字和姓氏值。

foreach ($response->records as $record) {
    $sObject = new SObject($record);
    echo "<p>$sObject->Id</p>";
    echo "<p>$sObject->Name</p>";
}