why use elixir code example

Example 1: elixir if statement

iex> if true do
...>   "This works!"
...> end
"This works!"

iex> unless true do
...>   "This will never be seen"
...> end
nil

iex> if nil do
...>   "This won't be seen"
...> else
...>   "This will"
...> end
"This will"

Example 2: elixir function arity

inspect :erlang.fun_info(fn -> :ok end)[:arity] 
inspect :erlang.fun_info(fn a,b-> a+b end)[:arity] 
inspect fn a,b-> a+b end |> is_function 
inspect fn a,b-> a+b end |> is_function(1)