Sort an array by keys based on specified order (without changing association)

sort_array_by_key_order.php

<?php
// Our initial array
$array_in = [
    'L' => 'foo',
    'R' => 'bar',
    'skibidi' => 'wapwapwap',
    3 => 'baz',
    'V' => 'qux',
];

// The desired sort, adding a non-existent key and forgetting another to see what happens
$array_order = ['V', 'L', 3, 'foo', 'R'];

// The sorted array
$array_out = array_replace(array_flip($array_order), $array_in);

/*
Result: The non-existent key is added with its position as a value and the forgotten value is added at the end.

array (
  'V' => 'qux',
  'L' => 'foo',
  3 => 'baz',
  'foo' => 3,
  'R' => 'bar',
  'skibidi' => 'wapwapwap',
)
*/

// Another approach
$array_out2 = [];
foreach($array_order as $index => $key_name) {
    if(array_key_exists($key_name, $array_in)) {
        $array_out2[$key_name] = $array_in[$key_name];
    }
    else {
        $array_out2[$key_name] = null;
    }
}

/*
Result: The non-existing key is added with NULL as value.

array (
  'V' => 'qux',
  'L' => 'foo',
  3 => 'baz',
  'foo' => NULL,
  'R' => 'bar',
)
*/