Rsa97

Promise.all(
  URL.map(
    (url) => fetch(url)
      .then((response) => `${url} : ${response.status} ${response.statusText}`)
      .catch((e) => `${url} : ${e.message}`),
  ),
)
.then(
  (results) =>
    alert(results.join("\n")),
);

var unresolved = URL.length;
var results = [];
for (i = 0; i < URL.length; i += 1) {
  (function(i) {
    var request = new XMLHttpRequest();
    request.open("GET", URL[i]);
    request.onreadystatechange = function (event) {
      console.log(request);
      if (request.readyState === 4) {
        if (request.status === 200) {
          results[i] = URL[i] + ' РАБОТАЕТ';
        } else {
          results[i] = URL[i] + ' НЕ РАБОТАЕТ';
        }
        unresolved -= 1;
        console.log(unresolved);
        if (unresolved === 0) {
          alert(results.join("\n"));
        }
      }
    }
    request.send();
  })(i);
}

$localKeys = array_column($arr1, 'product');
$remoteKeys = array_column($arr2, 'product');
$totalKeys = array_values(array_unique(array_merge($localKeys, $remoteKeys)));

$localLinks = array_combine(
    $localKeys,
    array_column($arr1, 'local_link')
);
$remoteLinks = array_combine(
    $remoteKeys,
    array_columns($arr2, 'remote_link')
);

$result = array_map(
    fn($key) => [
        'product' => $key,
        'local_link' => $localLinks[$key] ?? null,
        'remote_link' => $remoteLinks[$key] ?? null
    ]
);

const reverseArray = (arr) =>
  arr.reduceRight((acc, item) => (acc.push(item), acc), []);

const reverseArrayInPlace = (arr) => {
  for (let i = 0, j = arr.length - 1; i < j; i += 1, j -= 1) {
    [arr[i], arr[j]] = [arr[j], arr[i]];
  }
};

WITH RECURSIVE `cte` (`id`, `parent_id`, `title`, `n`) AS (
  SELECT `id`, `parent_id`, `title`, 0
    FROM `table`
    WHERE `id` = :categoryId
  UNION
  SELECT `t`.`id`, `t`.`parent_id`, `t`.`title`, `n`+1
    FROM `cte`
    JOIN `table` AS `t` ON `t`.`id` = `cte`.`parent_id`
)
SELECT `id`, `title`
  FROM `cte`
  ORDER BY `n` DESC

const arr1 = [
  [ 432432, 23423, 123123, 54364346],
  [ 756456, 2423423, 645654, 23423423],
  [ 12354, 123123, 23423423, 1235765]
]

const arr3 = [ 12354, 5345, 53456346 ]

const arrResult = arr1
  .flat(Infinity)
  .filter(el => arr3.includes(el))

console.log(arrResult)

// Array [ 12354 ]

const arr1 = [
  [ 432432, 23423, 123123, 54364346],
  [ 756456, 2423423, 645654, 23423423],
  [ 12354, 123123, 23423423, 1235765]
]

const arr3 = [ 12354, 5345, 53456346 ]

const arr1s = arr1.flat(Infinity)
arr1s.sort((a, b) => a - b)

const arr3s = arr3.slice()
arr3s.sort((a, b) => a - b)

const arrResult = []

for (let i = 0, let j = 0; i < arr1s.length, j < arr3s.length;) {
  if (arr1s[i] === arr3s[j]) {
    arrResult.push(arr1s[i])
    i += 1
  } else if (arr1s[i] < arr3s[j]) {
    i += 1
  } else {
    j += 1
  }
}

console.log(arrResult)

// Array [ 12354 ]