Calculate total price in Elixir, see https://twitter.com/ThaddeusJiang/status/1317388280724287488?s=20

jstore.ex

defmodule Jstore do
  @moduledoc """
  Documentation for `Jstore`.
  """

  @doc """
  Hello world.

  ## Examples

      iex> Jstore.total_price(:china_jzh, 100)
      100

  """
  def total_price(:china_jzh, price) do
    if price >= 100 do
      price
    else
      price + price * 0.03
    end
  end

  def total_price(:china_others, price) do
    price + price * 0.03
  end

  def total_price(:australia, price) do
    price + price * 0.05 + price * 0.1
  end

  def total_price(:others_country, price) do
    price + price * 0.07 + price * 0.17
  end
end