Array Functions

insertArrayPos.php

<?php
function arrayInsertInPos(
    $needle,
    array &$haystack,
    $pos,
    $preserve = false,
    $recursive = false
): array {

    $keys = array_filter(
        array_intersect(array_keys($needle), array_keys($haystack)),
        'is_string'
    );

    if (\is_array($pos)) {
        $key = $pos[0];
        $before = (isset($pos[1]) && $pos[1] === true) ?: false;
        $pos = array_search($key, array_keys($haystack), true);
        $pos = $before ? $pos : $pos + 1;
    }

    if ($keys) {
        $arr =& $haystack;
        if ($preserve) {
            $arr =& $needle;
        }

        foreach ($keys as $key => $value) {
            unset($arr[$value]);
        }
    }

    $start = array_splice($haystack, 0, (int)$pos);
    $func = $recursive ? 'array_merge_recursive' : 'array_merge';
    $haystack = $func($start, (array)$needle, $haystack);

    return $haystack;
}