How to read from STDIN in Elixir (for HackerRank)

example.ex

defmodule Solution do
#Enter your code here. Read input from STDIN. Print output to STDOUT
end

array_length = IO.read(:stdio, :line)
array = IO.read(:stdio, :line)

array_length
    |> String.trim
    |> String.to_integer
    |> IO.puts

array
    |> String.split(" ")
    |> Enum.map(fn n -> String.to_integer(n) end)
    |> IO.inspect

Here's an alternative https://gist.github.com/samuelralak/88ba2751a2c2d4eddb7ff7d36ab1df6a

input = IO.read(:stdio, :all)
  |> String.split("\n")
  |> Enum.map(fn x -> Integer.parse(x) |> elem(0) end)
  
[n | elements] = input
Solution.function_name(n, elements)

If you need all lines:

defmodule Solution do
  def run(n, elements) do
    IO.inspect n, label: "n"
    IO.inspect elements, label: "elements"
    IO.puts "your solution here"
  end
end

input =
  IO.read(:stdio, :all)
  |> String.split("\n")

[n | rest] = input

lines = Enum.map(rest, fn line ->
  line
  |> String.split(" ")
  |> Enum.map(&String.to_integer/1)
end)

Solution.run(n, lines)

defmodule Solution do  
    IO.read(:stdio, :all) 
    |> String.split("\n") 
    |> Enum.map(&(String.to_integer(&1))) 
    |> Enum.sum()
    |> IO.inspect()
end

https://gist.github.com/uxjp/e8e73a121f2d6563718db58eb3332c3a

Here is different solution, not using pipes all the way. I'm just beggining with Elixir, will I do everything with pipes in the future ?

Here is different solution, not using pipes all the way. I'm just beggining with Elixir, will I do everything with pipes in the future ?

FWIW you don't have to use the pipe operator |> at all, but it is seen as somewhat idiomatic in Elixir. See: https://elixirschool.com/en/lessons/basics/pipe_operator

FWIW

Thanks for the advice Simon.