in_array的匿名PHP函数不起作用

Question

I have this simple array $tree in PHP that I need to filter based on an array of tags matching those in the array.

Array
(
    [0] => stdClass Object
        (
            [name] => Introduction
            [id] => 798162f0-d779-46b6-96cb-ede246bf4f3f
            [tags] => Array
                (
                    [0] => client corp
                    [1] => version 2
                )
        )

    [1] => stdClass Object
        (
            [name] => Chapter one
            [id] => 761e1909-34b3-4733-aab6-ebef26d3fcb9
            [tags] => Array
                (
                    [0] => pro feature
                )
        )
)

I tried using an anonymous function like so:

$selectedTree = array_filter($tree, function($array) use ($selectedTags){
   return in_array($array->tags, $selectedTags, true);
});

$selectedTags:

Array
(
    [0] => client corp
)

The above is returning empty when I'd expect item 1 to be returned. No error thrown. What am I missing?

Answer 1

In case of in_array($neddle, $haystack) . the $neddle must need to be a String , but you're giving an array that is why its not behaving properly.

But if you like to pass array as value of $selectedTags then you might try something like below:

$selectedTree = array_filter($tree, function($array) use ($selectedTags){
   return count(array_intersect($array->tags, $selectedTags)) > 0;
});

Ref: array_intersect

Answer 2

If I am reading the question correctly, you need to look at each object in $tree array and see if the tags property contains any of the the elements in $selectedTags

Here is a procedural way to do it.

$filtered = array();
foreach ($tree as $key => $obj) {
    $commonElements = array_intersect($selectedTags, $obj->tags);
    if (count($commonElements) > 0) {
        $filtered[$key] = $obj;
    }
}

I was going to also post the functional way of doing this but, see thecodeparadox's answer for that implementation.