如何将元素添加到 SimpleXMLElement 对象内的数组中

Question

我使用 SimpleXML 解析了该对象：

SimpleXMLElement Object
(
[contact] => SimpleXMLElement Object
    (
        [name] => Some guy
        [number] => **********
    )

[messages] => SimpleXMLElement Object
    (
        [msg] => Array
            (
                [0] => SimpleXMLElement Object
                    (
                        [from] => Some guy
                        [message] => Hey
                        [5] => SimpleXMLElement Object
                            (
                            )

                    )

                [1] => SimpleXMLElement Object
                    (
                        [from] => Qasim Iqbal
                        [message] => Hows it going?
                    )

                [2] => SimpleXMLElement Object
                    (
                        [from] => Some guy
                        [message] => Not bad... just doing some homework
                    )

                [3] => SimpleXMLElement Object
                    (
                        [from] => Some guy
                        [message] => Im just kidding I'm playing games
                    )

                [4] => SimpleXMLElement Object
                    (
                        [from] => Qasim Iqbal
                        [message] => lol...
                    )

            )

    )

)

在我的 PHP 文件中，该对象名为 $chat。 我的目标是向 [msg] 数组添加另一个元素，使完整数组如下所示：

[msg] => Array
        (
            [0] => SimpleXMLElement Object
                (
                    [from] => Some guy
                    [message] => Hey
                )

            [1] => SimpleXMLElement Object
                (
                    [from] => Qasim Iqbal
                    [message] => Hows it going?
                )

            [2] => SimpleXMLElement Object
                (
                    [from] => Some guy
                    [message] => Not bad... just doing some homework
                )

            [3] => SimpleXMLElement Object
                (
                    [from] => Some guy
                    [message] => Im just kidding I'm playing games
                )

            [4] => SimpleXMLElement Object
                (
                    [from] => Qasim Iqbal
                    [message] => lol...
                )

            [5] => SimpleXMLElement Object
                (
                    [from] => Some guy
                    [message] => what are you laughing at?
                )

        )

注意如何添加键为“5”的元素。我试图这样做：

$chat->messages->msg->addChild(sizeof($chat->messages->msg));

但由于某种原因，这不起作用，因为 $chat->messages->msg 自动定义为 $chat->messages->msg[0]，而不是整个数组。可能是什么问题？

Answer 1

print_r 输出中的“数组”并不是真正的数组 - 这只是 PHP 试图向您显示 SimpleXML 对象的状态，该对象有 4 个子元素，全部称为 < /code>

->addChild() 方法需要在要创建子节点的父节点上运行。

$chat->messages->msg 将返回带有标签名称 的 messages 的所有子节点的列表;正如您所发现的，如果 SimpleXML 需要对单个元素进行操作，它将假定您想要该列表中的第一项。

这些都不是您想要的 - 您想要向节点 $chat->messages 添加一个新的 子节点，然后是该节点的两个子节点（ 和 节点）。

试试这个：

$new_item = $chat->messages->addChild('msg');
$new_item->addChild('from', 'Some guy');
$new_item->addChild('message', 'what are you laughing at?');

Answer 2

SimpleXML 做了很多自动类型强制，这会让事情变得非常混乱。你尝试过这样的事情吗？

$messages = (array) $chat->messages;
$messages[] = (object) array(
  'from' => 'Barak Obama',
  'message' => 'I love you.',
);