data_get.php

<?php 

/**
 * Get an item from an array using "dot" notation.
 * Provides a safe way to access nested array values,
 * and also return a default value if the key does not exist.
 * 
 * @param array $data
 * @param string|int $key
 * @param mixed $default
 * @return mixed
 */
function data_get($data, $key, $default = null) {
    if (is_null($key)) {
        return $data;
    }

    if (is_array($key)) {
        $return = [];

        foreach ($key as $k) {
            $return[$k] = data_get($data, $k, $default);
        }

        return $return;
    }

    foreach (explode('.', $key) as $segment) {
        if (!is_array($data) || !array_key_exists($segment, $data)) {
            return $default;
        }

        $data = $data[$segment];
    }

    return $data;
}