linjunpop · May 30, 2021 11:14 · linjunpop · May 30, 2021
diff --git a/concat.ex b/concat.ex
 defmodule Concat do
  def join(a, b) do
    IO.puts "***First join"
    a <> b
  end

  def join(a, b, sep \\ " ") do
    IO.puts "***Second join"
    a <> sep <> b
  end
 end
diff --git a/math.ex b/math.ex
 defmodule Math do
  def sum(a, b) do
    a + b
  end
 end
	defmodule Concat do
	def join(a, b) do
	IO.puts "***First join"
	a <> b
	end

	def join(a, b, sep \\ " ") do
	IO.puts "***Second join"
	a <> sep <> b
	end
	end