Intermediate Exercism • elixir

Two Fer

Challenge Overview

Create a sentence of the form "One for X, one for me.".

Introduction

In some English accents, when you say “two for” quickly, it sounds like “two fer”. Two-for-one is a way of saying that if you buy one, you also get one for free. So the phrase “two-fer” often implies a two-for-one offer.

Imagine a bakery that has a holiday offer where you can buy two cookies for the price of one (“two-fer one!”). You take the offer and (very generously) decide to give the extra cookie to someone else in the queue.

Instructions

Your task is to determine what you will say as you give away the extra cookie.

If you know the person’s name (e.g. if they’re named Do-yun), then you will say:

One for Do-yun, one for me.

If you don’t know the person’s name, you will say you instead.

One for you, one for me.

Here are some examples:

Name	Dialogue
Alice	One for Alice, one for me.
Bohdan	One for Bohdan, one for me.
	One for you, one for me.
Zaphod	One for Zaphod, one for me.

Source: Exercism elixir/two-fer

💡 View Solution

defmodule TwoFer do
  def two_fer(name \\ "you"), do: "One for #{name}, one for me."
end