Classy Ruby enumerating

05 Jan 2016 Given two users:

User.create(first_name: "Joe", last_name: "Louis")
#=> User id: 1, first_name: "Joe", last_name: "Louis"

User.create(first_name: "Muhammed", last_name: "Ali")
#=> User id: 2, first_name: "Muhammed", last_name: "Ali"

Say you want to get an array of arrays, with each individual array containing two elements: the first and last name, and the id. You could do something like this, which is perfectly valid but also gross to read:

User.pluck(:id, :first_name, :last_name).map do |user|
  id = user[0]
  first = user[1]
  last = user[2]
  ["#{first} #{last}", id]
end

However, it’s much more readable to use tuple syntax:

User.pluck(:id, :first_name, :last_name).map do |(id, first, last)|
  ["#{first} #{last}", id]
end
#=> [
      ["Joe Louis", 1],
      ["Muhammed Ali", 2]
    ]