- var_export: documentation ( source)
- in_array: documentation ( source)
- uksort: documentation ( source)
<?php
$array = [
'a' => 2,
'z' => 2,
'd' => 1
];
$allowlist = ['a', 'd'];
uksort(
$array,
fn($a, $b) =>
[$array[$b], in_array($b, $allowlist)]
<=>
[$array[$a], in_array($a, $allowlist)]
);
var_export($array);