How to assign a default value to a variable if the first condition fails?

Question

I have the following expression in Ruby:

env = opts.env || "staging"

How to record it in Elixir?

EDIT:

This expression in Elixir will not work:

 case Repo.insert(changeset) do {:ok, opts} -> env = opts.env || "staging" 

Error:

 ** (KeyError) key :env not found in: %Myapp.App{__meta__: #Ecto.Schema.Metadata<:loaded> 

Answer 1

Exactly the same idiom job (assuming "unsuccessfully" that you mean opts.env is zero):

 iex(1)> nil || "staging" "staging" iex(2)> "production" || "staging" "production" 

An elixir, like Ruby, treats nil as a value of falsity.

Answer 2

For completeness, this will also do what you want:

 e = "production" # Setting this only because I don't have an opts.env in my app. env = if !e, do: "staging", else: e #"production" e = nil env = if !e, do: "staging", else: e #"staging"