Php 从 xml 节点获取特定值(调用节点名称)

Question

XML

<CRates>
    <Currencies>
        <Currency>
            <ID>AED</ID>
            <Units>1</Units>
            <Rate>0.17200000</Rate>
        </Currency>
        <Currency>
            <ID>ATS</ID>
            <Units>1</Units>
            <Rate>0.04102750</Rate>
        </Currency>
    </Currencies>
</CRates>

想得到例如Rate值在哪里 ID是ATS

目前只能这样获取

$xmlDoc = simplexml_load_file('__joomla.xml');
echo $xmlDoc->Currencies->Currency[1]->Rate;

<ID>ATS</ID>在第二个<Currency>之内, 所以 Currency[1]

当然echo $xmlDoc->Currencies->Currency[ATS]->Rate;不起作用。但是有什么简单的方法可以让它发挥作用吗？

似乎需要使用 foreach如果 <ID>，则在 foreach 内部== ATS，回显<Rate>

Answer 1

试试这个:

// This way should work for all versions of PHP
$rate = false;
foreach ($xmlDoc->Currencies->Currency as $currency)
{
    if ((string)$currency->ID == 'ATS')
    {
        $rate = (string)$currency->Rate;
        break;
    }
}

// This way should work for newer versions of PHP only, I personally think that anonymous functions like this add to the readability which is why I included both options
$rate = call_user_func(function() use ($xmlDoc) {
    foreach ($xmlDoc->Currencies->Currency as $currency)
    {
        if ((string)$currency->ID == 'ATS')
            return (string)$currency->Rate;
    }
    return false;
});

// Using false to signify failure is the standard in PHP
if ($rate !== false)
    echo 'The rate is: ',$rate;
else
    echo 'Rate not found';

您可能不需要转换为字符串，但我相信如果您不这样做，您最终会得到 SimpleXMLElement 对象(或具有类似名称的对象)而不是字符串。