(PHP 4 >= 4.0.6, PHP 5, PHP 7, PHP 8)
key_exists — Псевдоним array_key_exists()
Функция — псевдоним функции: array_key_exists().
The key_exists() function has never been deprecatedhttps://bugs.php.net/bug.php?id=71174
Deprecated alias, don't use it. Will get removed sooner or later.