PHP在foreach循环中迭代simplexml

我有一个simplexml对象，如下所示

<?xml version="1.0"?>
<SalesInvoices xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://api.unleashedsoftware.com/version/1">
    <SalesInvoice>
        <OrderNumber>100</OrderNumber>
    </SalesInvoice>
    <SalesInvoice>
        <OrderNumber>101</OrderNumber>
    </SalesInvoice>
</SalesInvoices>

当我这样做时，我根本没有从循环中得到任何输出，甚至“hello”也不会打印。我做错了什么？

做什么

<?php

$string = '<?xml version="1.0"?>
<SalesInvoices xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://api.unleashedsoftware.com/version/1">
    <SalesInvoice>
        <OrderNumber>100</OrderNumber>
    </SalesInvoice>
    <SalesInvoice>
        <OrderNumber>101</OrderNumber>
    </SalesInvoice>
</SalesInvoices>';
$xml = simplexml_load_string($string);

foreach($xml as $SalesInvoice) {
    print $SalesInvoice->OrderNumber;
}

OrderNumber；
}

我已经编辑了回复。SalesInvoices（复数）是根元素，因此不需要将其导出。因为它只包含SaleInvoice元素，所以您可以直接

foreach（$xml

）

foreach（$xml->SaleInvoice…

（单数）也可以工作。需要记住的重要一点是

$xml

表示根节点，而不是抽象文档对象。

<?php

$string = '<?xml version="1.0"?>
<SalesInvoices xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://api.unleashedsoftware.com/version/1">
    <SalesInvoice>
        <OrderNumber>100</OrderNumber>
    </SalesInvoice>
    <SalesInvoice>
        <OrderNumber>101</OrderNumber>
    </SalesInvoice>
</SalesInvoices>';
$xml = simplexml_load_string($string);

foreach($xml as $SalesInvoice) {
    print $SalesInvoice->OrderNumber;
}