In part 9 of my Elixir journey I'll be showing how to create functions that are only visible within a module.
So far all the named functions I've used in this blog series have been public. Elixir does allow you to create a private function using the `defp` keyword.
defmodule Math do
defp add(a) do
fn (b) -> a + b end
def add_one(n) do
add_fun = add(1)
In this example, the `add_one` function is our public api and internally this function will use `add` to create a function that is later used to do the addition work.
The interesting bit here is that if we try to use the private function `add` we get an error because that function was declared using the `defp` keyword (macro).
`UndefinedFunctionError function Math.add/1 is undefined or private`