Bagaimana cara menggabungkan dua atau lebih array di PHP tanpa kehilangan nilai jika kuncinya sama dan nilainya berbeda

Inilah salah satu solusinya:

<?php
$arrayA = array(0 => 11, 2 => 12, 3 => 13, 4 => array(0 => 100, 1 => array(0 => 222),), 5 => 2, 6 => 3);
$arrayB = array(
    0 => 11,
    2 => 12,
    3 => 13,
    4 => array(
        0 => 100,
        1 => array(0 => array(0 => 'test1', 1 => 'test2'), 1 => array(0 => 'test1', 1 => 'test2'),),
    ),
    5 => 2,
    6 => 3
);


/**
 * @param $a
 * @param $b
 * @return array
 */
function array_merge_graceful($a, $b)
{
    $c = [];
    if (is_array($a) && is_array($b)) {
        foreach (array_merge(array_keys($a),array_keys($b)) as $i) {
            if (!array_key_exists($i, $a)) {
                $c[$i] = $b[$i];
            } elseif (!array_key_exists($i, $b)) {
                $c[$i] = $a[$i];
            } else {
                $c[$i] = array_merge_graceful($a[$i], $b[$i]);
            }
        }
    } else {
        if ($a <> $b) {
            $c = [$a, $b];
        } else {
            $c = $a;
        }
    }
    return $c;
}

var_dump(array_merge_graceful($arrayA, $arrayB));

?>

Cobalah sesuatu seperti ini

<?php

$array1 = array(11, 12, 13, array(100, 200), 2, 3);
$array2 = array(11, 12, 13, array(400, 500), 2, 3);
echo "<pre>";
print_r($array1);
print_r($array2);

$combine = array();

foreach ($array1 as $key => $value) {
    if (array_key_exists($key, $combine)) {
        //if is array
        if (is_array($combine[$key])) {
            $combine[$key] = array($combine[$key], $value);
        }
    } else {
        $combine[$key] = $value;
    }
}

foreach ($array2 as $key => $value) {
    if (array_key_exists($key, $combine)) {
        //if is array
        if (is_array($combine[$key])) {
            $combine[$key] = array($combine[$key], $value);
        }
    } else {
        $combine[$key] = $value;
    }
}

echo "<hr>";
print_r($combine);

gunakan fungsi array_merge_recursive() untuk menggabungkan array. Untuk lebih jelasnya silakan lihat http://php.net/manual/en/function.array-merge-recursive.php