Anonymous Functions in Elixir

Feb 6, 2020

While learning Elixir there are these little learning moments where the task would be simple in another language, but is a little more complex in a new language and new paradigm.

The task was to create an anonymous function that reacts to the value of the arguments.

From Programming Elixir:

If the first two are zero, return “FizzBuzz.” If the first is zero, return “Fizz.” If the second is zero, return “Buzz.” Otherwise return the third argument.

Seems simple enough, but I was stuck. Based on the examples I had to look back on, I was using the wrong syntax. Those examples used tuples, and I was passing in arguments directly.

Also, anonymous functions and their arguments can be a bit misleading. I thought I would need fn (a,b,c), but I actually leave that out, and just pattern match for those.

fizzbuzz = fn
  (0,0,_) -> "Fizz Buzz"
  (0,_,_) -> "Fizz"
  (_,_,c) ->  c


Then I tried to run it in an iex console. I could load it with iex fizzbizz.exs, but couldn’t call the function. Nothing worked.

I just decided to run it with elixir directly and print out the result of calling the function within the file.

elixir fizzbuzz.exs