如果一个或多个数组为空，则merge_array返回null？ [英] merge_array returns null if one or more of arrays is empty?

问题描述

我将为您快速介绍我的工作。

I will give you quick run down of what I am doing.

我正在将wordpress与高级自定义字段插件。这是一个基于php的问题，因为这些 get_field（）字段包含对象数组。

I am using wordpress with the advanced custom fields plugin. This is a php based question because these get_field() fields contain object arrays.

$gallery_location   = get_field('gallery_location');
$gallery_studio = get_field('gallery_studio');

例如 $ gallery_location 会在转储时返回此...

For example $gallery_location when dumped will return this...

array(18) {
  [0]=>
  array(10) {
    ["id"]=>
    int(126)
    ["alt"]=>
    string(0) ""
    ["title"]=>
    string(33) "CBR1000RR STD Supersport 2014 001"
    ["caption"]=>
    string(0) ""
    ["description"]=>
    string(0) ""
    ["mime_type"]=>
    string(10) "image/jpeg"
    ["url"]=>
    string(94) "http://www.example.com/wp/wp-content/uploads/2013/10/CBR1000RR-STD-Supersport-2014-001.jpg"
    ["width"]=>
    int(7360)
    ["height"]=>
    int(4912)
  }
... on so fourth
}

然后我使用merge_array合并两个对象...

I am then using merge_array to merge both objects...

$gallery_location = get_field('gallery_location');
$gallery_studio = get_field('gallery_studio');

$downloads = array_merge( $gallery_location, $gallery_studio );

我正在合并多个数组，但是如果其中一个数组为空，则会导致合并数组

I am merging multiple arrays but if one of the arrays is empty then this is causing the merge array to return null entirely!

我的问题是如何停止merge_array返回null，因为某些数组为空？

My question is how can I stop merge_array returning null is some of the arrays are empty?

预先感谢您的任何想法。

Thanks in advance for any ideas.

@zessx

这就是我要返回的内容...

This is what I am returning...

$gallery_location   = get_field( 'gallery_location' );
$gallery_studio     = get_field( 'gallery_studio' );

$downloads = array_merge( $gallery_location, $gallery_studio );

var_dump($gallery_location);

var_dump($gallery_studio);

var_dump($downloads);

，这些都是上述转储的相同顺序的结果。 。

and these are the results of dumps above in same order...

string(0) ""

array(18) {
  [0]=>
  array(10) {
    ["id"]=>
    int(126)
    ["alt"]=>
    string(0) ""
    ["title"]=>
    string(33) "CBR1000RR STD Supersport 2014 001"
    ["caption"]=>
    string(0) ""
    ["description"]=>
    string(0) ""
    ["mime_type"]=>
    string(10) "image/jpeg"
    ["url"]=>
    string(94) "http://www.example.com/wp/wp-content/uploads/2013/10/CBR1000RR-STD-Supersport-2014-001.jpg"
    ["width"]=>
    int(7360)
    ["height"]=>
    int(4912)
  }
... on so fourth
}

NULL

您可以看到 $ downloads 仍然返回null，如果我尝试同时使用下面的两个解决方案都行不通？

As you can see $downloads is still returning null, if I try and use both your solution below it does not work?

推荐答案

array_merge 仅接受数组作为参数。如果您的参数之一为null，则会引发错误：

array_merge only accepts arrays as parameters. If one of your parameters is null, it will raise an error :

警告：array_merge（）：参数#x不是数组。 ..

Warning: array_merge(): Argument #x is not an array...

如果其中一个数组为空，则不会引发此错误。空数组仍然是数组。

This error won't be raised if one of the arrays is empty. An empty array is still an array.

两个选项：

1 /强制类型为是 array

1/ Force the type to be array

$downloads = array_merge( (array)$gallery_location, (array)$gallery_studio );

2 /检查变量是否为数组

$downloads = array();
if(is_array($gallery_location))
    $downloads = array_merge($downloads, $gallery_location);
if(is_array($gallery_studio ))
    $downloads = array_merge($downloads, $gallery_studio);

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