[Ruby] Define the hierarchy at the same time as Hash initialization with tap method

I think it's written in a reference book, but instead of a memorandum.

For example

When you want to separate an array containing multiple elements such as the following with an associative array

array = [1, 2, "a", 3, "b", "c", 4]

ideal_hash = {
  hoge: [1, 2, 3, 4],
  fuga: ["a", "b", "c"]
}

The code I've written so far

ideal_hash = { hoge: [], fuga: [] }

array.each do |i|
  i.is_a?(Integer) ? hash[:hoge] << i : hash[:fuga] << i
end

I recently learned that I can write this too

Since the tap method returns the generated self, I can write it neatly, and I want to use it as much as possible.

ideal_hash = { hoge: [], fuga: [] }.tap do |hash|
  array.each do |i|
    i.is_a?(Integer) ? hash[:hoge] << i : hash[:fuga] << i
  end
end