programming-elixir-ch4-data-types.ex

# Basic Data Types in Elixir

# Atoms
name = :willson # an atom's name is its value
full_name = :willson_mock # underscores and other symbols are also valid in atom names

# Tuple
result = { :ok, "Hello World" }
{ response, message } = result # Tuples are often used in pattern matching

# Lists
empty_list = [] # A list can either be empty...
non_empty_list = [1, 2] # Or it can consist of a head value (i.e. 1) and a tail list (i.e. [2])
long_way_to_build_list = [ 1 | [ 2 ] ] # this is the same as [1, 2]

# Map
person = %{ name: "Willson", weight: 150 }
friend = %{ "name" => "Kanye", occupation: "Rapper" }

IO.puts(person.name) # This will work and print out "Willson"
IO.puts(person[:weight]) # This will work and print out "150"
IO.puts(person["weight"]) # This will work but will return nil because "weight" and :weight are not the same

IO.puts(friend["name"]) # This will work and print out "Kanye"
IO.puts(friend[:name]) # This will work but will return nil because :name and "name" are not the same
IO.puts(friend.name) # This won't work and will throw an error because dot notation only works when the keys are atoms

# Keyword Lists
options = [ {:auto_indent, true}, {:max_characters: 255}, {:default_value: "Hello World"} ]
IO.puts(options) # When Elixir prints out a keyword list, it will use a shorthand notation like so: [auto_indent: true, max_characters: 255, default_value: "Hello World"]