array_splice_assoc.php

array_splice_assoc.php

<?php

// https://stackoverflow.com/questions/16585502/array-splice-preserving-keys/70576992#70576992

function array_splice_assoc(array &$input, int|string $offset, ?int $length = null, $replacement = []): array
{
    // Normalize offset
    $offset = match (true) {
        is_string($offset) => array_flip(array_keys($input))[$offset] ?? throw new OutOfBoundsException(),
        $offset < 0 => count($input) + $offset,
        default => $offset,
    };

    // Normalize length
    $length = match (true) {
        $length === null => count($input) - $offset,
        $length < 0 => count($input) + $length - $offset,
        default => $length,
    };

    // Manipulate each part
    $before = array_slice($input, 0, $offset, true);
    $removed = array_slice($input, $offset, $length, true);
    $after = array_slice($input, $offset + $length, null, true);

    // Merge parts, allowing the latter overrides the former
    $input = array_replace($before, (array)$replacement, $after);

    return $removed;
}