ネストした配列にドットでアクセス＋keyがなかったら例外

code:php

<?php

$getOrFail = function (string $key, array $data) {

$keys = explode(".", $key);

$current = $data;

$history = [];

foreach ($keys as $k) {

if (!is_array($current)) {

throw new Exception("type error");

}

$history[] = $k;

$current =

throw new Exception(implode(".", $history) . " is required");

}

return $current;

};