PHP将两个数组合并为第三个数组

$arr1 = [1, 2, 3];
$arr2 = [4, 5, 6];
$result = array_merge($arr1, $arr2);
print_r($result);

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
    [5] => 6
)

$arr1 = [1, 2, 3];
$arr2 = [3, 4, 5];
$result = $arr1 + $arr2;
print_r($result);

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
)

$arr1 = ['color' => ['red'], 2, 4];
$arr2 = ['color' => ['blue'], 5];
$result = array_merge_recursive($arr1, $arr2);
print_r($result);

Array
(
    [color] => Array
        (
            [0] => red
            [1] => blue
        )

    [0] => 2
    [1] => 4
    [2] => 5
)