试图获得非对象的属性 - ＆gt;我该如何检查对象存在

Question

如何在使用Dom Document时检查对象是否存在，因为我正在获取

  

错误“试图获取非对象的属性”

$getplacename            = '//table//tr';
$getplacename2           = $xpath->query($getplacename);
//loop through each individual card
foreach($getplacename2 as $getplacename22) {

echo  $getplacename22 ->childNodes->item(0)->childNodes->item(2)->textContent;
echo  $getplacename22 ->childNodes->item(4)->textContent;
echo "<br /><br /><br />";
}

Answer 1

嗯，我认为最简单的方法是将代码更改为类似的内容（假设错误发生在以下行之一）：

foreach($getplacename2 as $getplacename22) {
    if ($getplacename22->childNodes->item(0) != null && $getplacename22->childNodes->item(0)->childNodes->item(2) != null) {
        echo $getplacename22->childNodes->item(0)->childNodes->item(2)->textContent;
    }
    if($getplacename22 ->childNodes->item(4) != null) {
        echo $getplacename22->childNodes->item(4)->textContent;
    }
    echo "<br /><br /><br />";
}