Exercism: Hello World

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Exercism: Hello World

Pau Riosa's photo
Pau Riosa
ยทMar 11, 2021ยท

3 min read

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This is the first time that I tried exercism.io . For me it is a website that trains you on how far can you learn a specific programming language. At first I was hesitant but at some point I gave it a shot.

The track that I choose is Elixir

Just for a brief background;

Elixir is a dynamic, functional language for building scalable and maintainable applications.

So if want to give a shot Elixir. That will be cool.

But anyway, The first challenge that I tried is the Hello World challenge. So the challenge was

The classical introductory exercise. Just say "Hello, World!". "Hello, World!" is the traditional first program for beginning programming in a new language or environment. The objectives are simple: Write a function that returns the string "Hello, World!".

  • Run the test suite and make sure that it succeeds.
  • Submit your solution and check it at the website.
  • If everything goes well, you will be ready to fetch your first real exercise.

So what I did was to run this code

defmodule HelloWorld do
  @doc """
  Simply returns "Hello, World!"
  """
  @spec hello :: String.t()
  def hello do
    "Hello, World!"
  end
end

Yeah, I know nothing much here! It is just a pretty short code that say's Hello, World!

For the meantime let me explain to you some parts that we used in order to show Hello, World!.

defmodule

defmodule is a macro that defines a module with the given alias as its name and with contents. --- Elixir

Okay? So what will be it's purpose?

So just like any other programming languages it defines the module that will handle all the necessary functions, flows and other stuff for us to create the Hello, World!

do end

Simply, it is equivalent to the open/close curly braces that we can see for example on C#, Javascript, and Java that tells us the scope of the process.

@doc

@doc is an attribute that helps developers to define the meaning and the behavior of the function. In our case, that is the hello/1 function that was define using def. It accepts String values.

def

def defines a public function with given name and body of the process.

@spec

@spec is also an attribute that tells developer the specifications of the function. Things like;

  • What data it will receive?
  • What data it will return?

Okay, so how are we gonna access those modules and functions to show Hello World?

So assuming you have an IEx open

> alias HelloWorld
> HelloWorld.hello()
> "Hello, World!"

And that's it!

That is how I solve showing the Hello, World!

I know you've got a lot of questions to ask and I know that too!

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