Access array key using uasort in PHP

Question

If have a rather basic uasort function in PHP that looks like this:

uasort($arr, function($a, $b) {
                if ($a > $b)
                    return -1;
                if ($a < $b)
                    return 1;
...
}

The array I'm trying to sort looks like the following:

{[1642] => 1, [9314] => 4, [1634] => 3 ...}

It contains integers that are my main comparison criteria. However, if the integers are equal, then I would like to access their key values, inside the uasort function and do some magic with it to figure out the sorting from there.

I have no clue how to do that as it seems that the $a and $b variables that get passed into the function are just the integers without the corresponding keys but there should be a way to access the key as well since I'm using a function to actually preserve the keys. Any ideas?

Answer 1

uksort($arr, function ($a, $b) use ($arr) {
    return $arr[$a] - $arr[$b] ?: $a - $b;
});

You can get the values by the keys, so use uksort which gives you the keys. Replace $a - $b with your appropriate magic, here it's just sorting by the key's value.