<?php

function flattenArray(array $array): array
{
    $result = [];
    foreach ($array as $element) {
        if (is_array($element)) {
            $result = array_merge($result, flattenArray($element));
        } else {
            $result[] = $element;
        }
    }
    return $result;
}

$nestedArray = [
    1,
    [2, 3],
    [4, [5, 6]],
    7,
    [8, [9, [10]]]
];

$flatArray = flattenArray($nestedArray);
print_r($flatArray);
// Output: Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8 [8] => 9 [9] => 10 )

$data = [
    'user_info' => ['name' => 'Alice', 'email' => 'alice@example.com'],
    'products' => [
        ['id' => 1, 'name' => 'Laptop'],
        ['id' => 2, 'name' => 'Mouse']
    ],
    'settings' => ['theme' => 'dark']
];

// Note: This flattens all values. For structured data, consider a different approach.
$flatData = flattenArray($data);
print_r($flatData);
/* Output:
Array
(
    [0] => Alice
    [1] => alice@example.com
    [2] => 1
    [3] => Laptop
    [4] => 2
    [5] => Mouse
    [6] => dark
)
*/

?>