elixir_002: Modules and functions

default_arguments.ex

defmodule Names do
  def full_name(name, surname, title \\ "Mr") do
    title <> " " <> String.capitalize(name) <> " " <> String.capitalize(surname)
  end
end

Names.full_name("john", "doe")            # Mr John Doe
Names.full_name("melissa", "doe", "Ms")   # Ms Melissa Doe

function_capturing.ex

defmodule Names do
  def full_name(name, surname) do
    String.capitalize(name) <> " " <> String.capitalize(surname)
  end
end

fun = &Names.full_name/2
# &Names.full_name/2

fun.("John", "Doe")
# "John Doe"

module.ex

defmodule Names do
  def full_name(name, surname) do
    name <> "" <> surname
  end

  def capitalized_name(name) do
    String.capitalize(name)
  end
end

pattern_matching.ex

defmodule Names do
  def full_name(name) do
    String.capitalize(name)
  end

  def full_name(name, surname) do
    String.capitalize(name) <> " " <> String.capitalize(surname)
  end
end

Names.full_name("john")               # John
Names.full_name("john", "doe")        # John Doe
Names.full_name("john", "doe", "jr")  # (UndefinedFunctionError) undefined function: Names.full_name/3

simple_clauses.ex

defmodule Names do
  def name(name, married)  when married == true do
    "Mrs" <> " " <> String.capitalize(name)
  end

  def name(name, married)  when married == false do
    "Ms" <> " " <> String.capitalize(name)
  end
end

Names.name("melissa", true)  # Mrs Melissa
Names.name("Hilary", false)  # Ms Hilary