Question

我有一个像这样的XML文件：

<devices>

<device name="Cabina" altid="e2" id="42" category="3"
    subcategory="0" room="3" parent="40" status="1" state="-1" comment=""/>

<device name="contatto finestra cucina" altid="12" id="28" category="4"
    subcategory="3" room="1" parent="1" armed="0" tripped="1"
    lasttrip="1398337234" batterylevel="1" heatsp="19" status="1"/>

<device name="Ingresso" altid="e1" id="15" category="3"
    subcategory="0" room="1" parent="14" status="0" state="-1" comment=""/>

</devices>

我想总结属于类别3的设备的状态。

在这种情况下，sum = 1。

由于

Answer 1

使用XPath表达式：

选择设备节点：/devices/device

如果category属性为3：/devices/device[@category = 3]

获取状态属性：/devices/device[@category = 3]/@status

总结一下：sum(/devices/device[@category = 3]/@status)

$dom = new DOMDocument();
$dom->loadXml($xml);
$xpath = new DOMXpath($dom);

var_dump($xpath->evaluate('sum(/devices/device[@category = 3]/@status)'));

输出：https://eval.in/182688

float(1)

Answer 2

$xml = simplexml_load_file('example.xml');
$sum=0;
foreach($xml as $device)
{
 if($device->category==3)
 {
  $sum+=$device->status;
 }
}
echo $sum;

php sum具有特定属性的XML属性

2 个答案: