merging parts (branches) of associative arrays

Question

I seem to get stuck at a (at first glance) simple thing: I have a nested assoc array ie

"stock" => [
    123 => [
            3 => 17,
            5 => 5,
            7 => 0
        ],
    456 => [
            3 => 1,
            5 => 3,
            7 => 7
        ]
]

These represent stocks of items (123 and 456) in warehouses (3, 5 and 7). Now I want to update stock in one warehouse for one item ie

"stock" => [
    123 => [
            3 => 11
        ]
]

I have tried to approach this via array_merge (re-keys the array) and array_merge_recursive (strangely does the same while it shouldn't - are numeric keys the reason?) but to no avail. Also I found this interesting bit https://vancelucas.com/blog/php-array_merge-preserving-numeric-keys/ but that replaces the entire branch of the array (so I'm losing warehouses 5 and 7).

Does anyone have some clever idea about this?

Answer 1

This should be enough:

$newArray = array_replace_recursive($sourceArray, $newDataArray);

Fiddle here https://3v4l.org/qdejB

Answer 2

Here is your snippet,

foreach ($temp['stock'] as $key => &$value) {
    foreach ($value as $key1 => $value1) {
        // no need to check, it will add at respective key matching
        $arr['stock'][$key][$key1] = $value1;    
    }
}

working demo .

Answer 3

如果我错了，请纠正我，但似乎没有什么能阻止您：

$foo['stock'][123][3] = 11;