MDN is currently in maintenance mode. Content is being served from a backup database, which means some articles may show out-of-date information. Have no fear! All will be restored when maintenance has concluded.
MDN 目前处于维护模式。内容目前从备份数据库提供，因此部分文章显示的信息可能陈旧。无需恐惧！所有信息将在维护结束后恢复。