array_dig.php

<?php

/**
 * Looks up a value at given path in an array subject
 *
 * @param array $subject The subject
 * @param string $path Delimited path of keys to follow
 * @param string $delimiter Path delimiter to use (defaults to .)
 * @return mixed The value at the given path if it exists; null otherwise
 */
function array_dig(array $subject, string $path, string $delimiter = '.') {
  foreach (explode($delimiter, $path) as $key) {
    if (! isset($subject[$key])) {
      return null;
    }
    $subject = $subject[$key];
  }
  return $subject;
}