PHP - Check if an array value is in another array - php

Question

So I have two arrays:
$gated_categories
array(2) { [0]=> int(3511) [1]=> int(3510) }
and
$category_id
array(3) { [0]=> int(3518) [1]=> int(3511) [2]=> int(3502) }
As you can see above, both arrays contain 3511
So if $gated_categories contains a value which is is $category_id
I want this to return true, else false
I have tried with this:
$is_gated = !array_diff($gated_categories, $category_id);
But this is returning false, any ideas?

Answer 1

array_diff() does the opposite of what you want. It returns an array with the values of the first array that are not present in the other array(s).
You need array_intersect().
if (count(array_intersect($arr1, $arr2))) {
//at least one common value in both arrays
}

Answer 2

You can do the following, loop over the array you want to check it's values and use in_array function.
Something like this:
<?php
function checkCategory(): bool {
$gated_categories = [3510, 3511];
$category_id = [3502, 3511, 3518];
foreach ($gated_categories as $cat) {
if (in_array($cat, $category_id)) {
return true;
}
}
return false;
}
var_dump(checkCategory());

Answer 3

You can solve this problem with use from array_diff two times
<?php
$gated_categories = [3511, 3510];
$category_id = [3518, 3511, 3502];
print_r(findGatedCategoriesContainCategoryId($gated_categories, $category_id));
function findGatedCategoriesContainCategoryId($gated_categories, $category_id) {
$arrayDiff = array_diff($gated_categories, $category_id);
return array_values(array_diff($gated_categories ,$arrayDiff));
}
?>
output
Array
(
[0] => 3511
)
Or just use array_intersect like this
<?php
$gated_categories = [3511, 3510];
$category_id = [3518, 3511, 3502];
$result = array_intersect($gated_categories, $category_id);
print_r($result);
?>
output
Array
(
[0] => 3511
)