使用单个XML定义，就像它是多个一样

Question

很难解释，让我试一试：我有这个XML：

<?xml version='1.0'?>
    <test>
        <a>
            <b>Lorem 1</b>
        </a>
        <a>
            <b>Lorem 2</b>
            <b>Lorem 3</b>
            <b>Lorem 4</b>
        </a>
    </test>

我正在使用PHP将其转换为这样的对象：

$obj = simplexml_load_string($xml);
print_r($obj) ;

它生成此Object输出：

SimpleXMLElement Object
(
    [a] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [b] => Lorem 1
                )
            [1] => SimpleXMLElement Object
                (
                    [b] => Array
                        (
                            [0] => Lorem 2
                            [1] => Lorem 3
                            [2] => Lorem 4
                        )
                )
        )
)

＆＃34; Lorem 1＆＃34;分配给＆＃34; b＆＃34;直接，但其他人转换成数组...

现在，如何制作＆＃34; Lorem 1＆＃34;像其他人一样??

SimpleXMLElement Object
(
    [a] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [b] => Array
                        (
                            [0] => Lorem 1 // like this!!

            [1] => SimpleXMLElement Object
                (
                    [b] => Array
                        (
                            [0] => Lorem 2
                            [1] => Lorem 3
                            [2] => Lorem 4