PHP multidimensional array search by value with random sub-level array - php

Question

Is it possible to search a multidimensional array of unknown depth by value?
For example, with:
$data = [
[
'uid' => '100',
'name' => 'MAIN',
[
'uid' => '2222',
'name' => 'SUB_MAIN',
[
'uid' => '8524',
'name' => 'SUB_SUB_MAIN',
]
]
],
[
'uid' => '5465',
'name' => 'MAIN',
],
[
'uid' => '40489',
'name' => 'MAIN',
]
];
I want to find the path to the sub-array where uid is 8524.
With the above array, the result should be: [0, 0, 0].

Answer 1

You can use the following as a starting point:
<?php
declare(strict_types=1);
error_reporting(-1);
ini_set('display_errors', 'On');
function findPath(array $items, callable $criteria, array $path = []): array {
foreach ($items as $key => $item) {
if (!is_array($item)) {
continue;
}
// prepare path to this item
$pathToHere = array_merge($path, [$key]);
// if the items fits the criteria
if ($criteria($item)) {
// return it's path
return $pathToHere;
}
// otherwise check children
$pathToChild = findPath($item, $criteria, $pathToHere);
// and if return value is not empty
if (count($pathToChild) > 0) {
// return path to child
return $pathToChild;
}
}
// base case if no item matches
return [];
}
$data = [
[
'uid' => '5465',
'name' => 'MAIN',
],
[
'uid' => '100',
'name' => 'MAIN',
[
'uid' => '2222',
'name' => 'SUB_MAIN',
[
'uid' => '8524',
'name' => 'SUB_SUB_MAIN',
[
'uid' => 'X',
'name' => 'Y',
]
],
[
'uid' => '8524_test',
'name' => 'SUB_SUB_MAIN_test',
[
'uid' => '8524_test_sub',
'name' => 'SUB_SUB_MAIN_test_sub',
]
]
]
],
[
'uid' => '40489',
'name' => 'MAIN',
]
];
$path = findPath($data, fn(array $item): bool => $item['uid'] === '8524_test_sub');
print_r($path);
/*
Array
(
[0] => 1
[1] => 0
[2] => 1
[3] => 0
)
*/
Demo: https://3v4l.org/XKTH8
Note the code above requires php 7.4, but only because of the fn() => ... construct. This could simply be replaced by any other suitable callable.