rails 撈數據庫轉array數組

User.all.map(&:id)  => [36, 37, 1, 2, 4, 6, 7, 8, 9, 10, 11, 14, 13, 15, 17, 18, 16, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 38, 12]

User.all.map(&:id).class => Array