5 things you need to remember in Elixir

Adam00
1 min readMar 28, 2021
  1. Single quotes vs double quotes
    A lot of modern programming languages, like ruby, javascript and python, will treat'string' the same as"string" . In Elixir, however, it is not the case
> 'string' == "string"
false
> IEx.Info.info('string')
... {"Data type", "List"} ...
> IEx.Info.info("string")
... {"Data type", "BitString"} ...

2. function clause for idiomatic elixir

defmodule AnimalSoundEmitter do
def emit(:dog), do: :bark
def emit(:cat), do: :meow
def emit(:snake), do: :hiss
def emit(:lion), do: :roar
end

3. guard clause

defmodule Calculator do
def plus(a, b) when is_number(a) and is_number(b), do: a + b
def minus(a, b) when is_number(a) and is_number(b), do: a - b
def multiply(a, b) when is_number(a) and is_number(b), do: a * b
def divide(a, b) when is_number(a) and is_number(b), do: a / b
end

4. assignment vs matching

assignment variable < is on the left side of the expression
matching < no error throws
matching with destructing, from Common Lisp
can match just a part of values

5. eex treats if/for as an expression

in ruby erb, no = applies before if/for

<% if true %>
This is correct
<% else %>
This is not
<% end %>

in elixir eex, a = is required

<%= if true %>
This is correct
<% else %>
This is not
<% end %>

Use haml, if you do not like eex

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Adam00

Let's go invent tomorrow instead of worrying about what happened yesterday.