Let's solve foobar

Going through different blogs reading about elixir and solving problems in general, I landed on this page. The problem seemed quite easy and I had already solved the same problem in other programming language before. I want to start learning elixir by solving this problem in elixir.

The task is to take integer n and print all number from 1 to n in different lines. If n is divisible by 3, then instead of printing 3, Foo needs to be printed, Bar if divisible by 5 and Foobar if divisible by 15.

Solution

for n <- 1..15 do
  cond do
    rem(n, 15) == 0 ->
      IO.puts "Foobar"
    rem(n, 3) == 0 ->
      IO.puts "Foo"
    rem(n, 5) == 0 ->
      IO.puts "Bar"
    true ->
      IO.puts n
  end
end

In most language, when required to check multiple conditions if...else if/elsif...else...end would be used, however elixir provides condfor such purpose. We can match any number of condition with cond and check the final condition with true -> which is equivalent to else.

If we only need to check only one condition, we use if...else...end macros.

IEX

iex(1)> if rem(10,2) == 0 do
...(1)>   IO.puts "Even" 
...(1)> else
...(1)>   IO.puts "Odd"
...(1)> end
Even
:ok