如何避免 PHP 通知“未定义偏移：0”而不检查数组的每个字段
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How to avoid PHP Notice "Undefined offset: 0" without checking each field of array
提问by maze
i have the following array:
我有以下数组：
$keyvisual_data = array(
'video_file' => $row->field_field_video[0]['rendered']['#item']['uri'],
'bild_file' => $row->field_field_bild[0]['rendered']['#item']['uri'],
'subline_src' => $row->_field_data['nid']['entity']->field_key_titel['und'][0]['safe_value'],
'screenreader_src' => $row->field_field_alt_screenreader[0]['rendered']['#markup'],
'alt_src' => $row->field_field_bild[0]['rendered']['#item']['alt']
);
it might happen that some of the fields are not set, this is okay. in fact i am getting this PHP notice:
可能会发生某些字段未设置的情况，这没关系。事实上，我收到了这个 PHP 通知：
Notice: Undefined offset: 0 in bafa_insert_keyvisual() ...........
注意：未定义的偏移量：bafa_insert_keyvisual() 中的 0 .....
is it somehow possible to assign a default value to each key in case it is undefined WITHOUT checking each field of the array manually?
是否有可能以某种方式为每个键分配一个默认值，以防未定义而不手动检查数组的每个字段？
thanks for help
感谢帮助
采纳答案by Dani
Yes, add @before the field like:
是的，@在字段前添加，如：
$keyvisual_data = array(
'video_file' => @$row->field_field_video[0]['rendered']['#item']['uri'],
'bild_file' => @$row->field_field_bild[0]['rendered']['#item']['uri'],
'subline_src' => @$row->_field_data['nid']['entity']->field_key_titel['und'][0]['safe_value'],
'screenreader_src' => @$row->field_field_alt_screenreader[0]['rendered']['#markup'],
'alt_src' => @$row->field_field_bild[0]['rendered']['#item']['alt']
);
and then initialize the nulls:
然后初始化空值：
if($keyvisual_data['video_file'] === null)
$keyvisual_data['video_file'] = $default_video_file;
etc...
等等...
回答by Naftali aka Neal
No there is not
不，那里没有
You can do an isset():
你可以做一个isset()：
if(isset($array[0])){
echo $array[0];
}
else {
//some error?
}
Or if you know that you are only going to be checking index 0:
或者，如果您知道您只会检查索引 0：
$array = $array + array(null);
So if the original $array[0]was unset, now it is null
因此，如果原始$array[0]未设置，现在是null
回答by Luke
You could add a shorthand check if each value is null
如果每个值都为空，您可以添加速记检查
$default_value = "Default value";
$keyvisual_data = array(
'video_file' => ($row->field_field_video[0]['rendered']['#item']['uri'] == null) ? $default_value : $row->field_field_video[0]['rendered']['#item']['uri']
// etc.. etc...
);
A less messy version of this, to explain the code more clearly:
一个不那么混乱的版本，更清楚地解释代码：
<?php
$default_value = "I am a Default value";
$video_file = null;
$new_array = array(
'video_file' => ($video_file == null) ? $default_value : $video_file
);
// Will output "I am a Default value"
echo $new_array['video_file'];
?>
回答by Nishu Tayal
You should use "isset" function to check the existence of the field, and infact its a good coding practice..
您应该使用“isset”函数来检查该字段的存在，事实上它是一个很好的编码实践。
$keyvisual_data = array(
'video_file' => isset($rowWrapper->getVideoFile()) ? $rowWrapper->getVideoFile() : "any default value",
...
);
or you can use it in this way :
或者你可以这样使用它：
if(isset($rowWrapper->getVideoFile()))
{
$row['video_file'] = $rowWrapper->getVideoFile();
}
else {
$row['video_file'] = "";
}
回答by Max
To be honest, the structure of the row data object doesnt seem very convinient and error prone. Especially if you are using $row in some other context, too, I would suggest you wrap it in an object:
老实说，行数据对象的结构似乎不太方便且容易出错。特别是如果您也在其他一些上下文中使用 $row ，我建议您将它包装在一个对象中：
class RowWrapper
{
private $_row;
public function __construct($row)
{
$this->_row = $row;
}
public function getVideoFile()
{
if (!isset($row->field_field_video[0])) {
return null;
}
return $row->field_field_video[0]['rendered']['#item']['uri'];
}
...
}
$rowWrapper = new RowWrapper($row);
$keyvisual_data = array(
'video_file' => $rowWrapper->getVideoFile(),
...
);
If you there is only one value e. g. inside of $row->field_field_videothen it shouldnt be an array. I would use a wrapper class as a kind of anti corruption layer if that strange datastructure comes from a remote source or the like. Otherwise it will creep through your while application with $row->field_field_video[0]...stuff all over the place.
如果你只有一个值，例如里面，$row->field_field_video那么它不应该是一个数组。如果那个奇怪的数据结构来自远程源等，我会使用包装类作为一种反腐败层。否则它会在你的 while 应用程序$row->field_field_video[0]...中到处都是东西。
I know this is not the fast and easy solution you want, but swallowing errors is never a good idea.
我知道这不是您想要的快速简便的解决方案，但吞下错误绝不是一个好主意。
