php递归合并数组

<?php
function deep_merge($array1, $array2) {
    $result = array_merge($array1, $array2);
    foreach ($result as $key => $value) {
        if (is_array($value) && isset($array1[$key]) && is_array($array1[$key])) {
            $result[$key] = deep_merge($array1[$key], $value);
        }
    }
    return $result;
}

$array1 = [
    'a' => 1,
    'b' => [
        'c' => 2,
        'd' => 3
    ]
];

$array2 = [
    'b' => [
        'd' => 4,
        'e' => 5
    ],
    'f' => 6
];

$mergedArray = deep_merge($array1, $array2);
print_r($mergedArray);
?>

Array
(
    [a] => 1
    [b] => Array
        (
            [c] => 2
            [d] => 4
            [e] => 5
        )

    [f] => 6
)