使用2D数组中的元素(不包括第一个)创建3D数组

Question

我有一个2D数组:

[["abc","def"],["ghi","jkl","mno"]]

我想在每个内部数组内部及其元素周围创建一个新数组(一个3D数组？),除了第一个,如下所示:

[["abc",["def"]],["ghi",["jkl","mno"]]]

Answer 1

arr = [["abc","def"],["ghi","jkl","mno"]]

arr.map { |first, *rest| [first, rest] }
  #=> [["abc", ["def"]], ["ghi", ["jkl", "mno"]]]