Need common arrays from two multidimensional arrays - php

Question

Hi I have below multidimensional arrays -
Array
(
[user_attempts] => 0
[2] => Array
(
[0] => 1
[1] => 4
)
[3] => Array
(
[0] => 32
[1] => 23
)
[4] => Array
(
[0] => asdsa
)
[1] => Array
(
[0] => Earth
)
)
and my second array is like below
Array
(
[1] => Array
(
[0] => Earth
)
[2] => Array
(
[0] => 2
[1] => 3
)
[3] => Array
(
[0] => 32
[1] => 23
)
[4] => Array
(
[0] => asdsa
[1] => asdas
)
)
I need to intersect both multidimensional arrays - so the result would be
Array
(
[1] => Array
(
[0] => Earth
)
[3] => Array
(
[0] => 32
[1] => 23
)
)
Can anyone help me to sort this out.
What I have tried is using array_intersect() but it limits to single array not multidimensional i guess.

Answer 1

PHP comes with a ton of functions already built in, but sometimes you still have to implement things yourself. What you want to do can be easily done by using the existing functions.
The goal is to do the following steps:
Find the keys that exist in both arrays
Loop through the array using these keys
Take the items of both input arrays with each of these keys
Calculate the intersection of those two arrays
Put it into a result array
Here is one way to do this:
function array_intersect_2dim (array $a1, array $a2) {
$keys = array_intersect(array_keys($a1), array_keys($a2));
$return = array();
foreach ($keys as $key) {
$return[$key] = array_intersect($a1[$key], $a2[$key]);
if (sizeof($return[$key]) == 0) {
unset($return[$key]);
}
}
return $return;
}
It works only for two dimensions. If you need more, you have to build a recursive approach, which follows the exact same principle.

Answer 2

To make the easier to compare you can use serialize/unserialize on this one. And then use array_intersect(). Try this example: Sample Output
$array1 = array( 'user_attemps' => 0, 2 => array(1, 4), 3 => array(32, 23), 4 => array('asdsa'), 1 => array('Earth'),);
$array2 = array( 1 => array('Earth'), 2 => array(2, 3), 3 => array(32, 23), 4 => array('asdsa', 'asdas'),);
$result = array_map('unserialize',array_intersect(array_map('serialize', $array1), array_map('serialize', $array2)));
print_r($result);