Write a New Function Inside of an Elixir Module
Elixir code is organized into groups of functions called modules. You can create your own modules and built on top of predefined modules that are a part of Elixir by default.
Additional resources:
Kyle Gill: [0:00] Almost all Elixir code is organized in modules. Modules is a group of related functions. Elixir has some modules like String and List built in and you can also define your own.
[0:10] Inside a defmodule declaration, you can define functions with the def keyword, using a function name and wrapping the code in the do and end keywords. Because Elixir supports implicit returns, you can write a string as the last line of the function, and it'll be returned when the function is called.
[0:25] To run the project, you can use the interactive Elixir shell and use -S mix as a parameter to compile your project and make your module available in the shell. The full command is iex -S mix. Then you can call a method on your module, HelloWorld.hello, and you can include or leave off parentheses.