merge_array returns null if one or more of arrays is empty?

Question

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

I am using wordpress with the advanced custom fields plugin. This is a php based question because these get_fiel

Answer 1

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

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

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

Two options :

1/ Force the type to be array

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

2/ Check if variables are arrays

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

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Answer 2

You can use the following way for merger your arrays:

$c = (array)$a + (array)$b