Overview

Elixir uses dynamic types based on Erlang where the type is determined by the data entered in the variable.

Data Types

Built-in types

1. Atom - literal constants with a name (true, false, and nil are atoms)
2. Float - numbers with floating point precision
3. Function - a reference to code chunk, created with the fn/1 special form
4. Integer - whole numbers (not fractions)
5. List - collections of a variable number of elements (linked lists)
6. Map - collections of key-value pairs
7. Process - light-weight threads of execution
8. Port - mechanisms to interact with the external world
9. Tuple - collections of a fixed number of elements

Data types without a module

1. Bitstring - a sequence of bits, created with Kernel.SpecialForms.«»/1. When the number of bits is divisible by 8, they are called binaries and can be manipulated with Erlang’s :binary module
2. Reference - a unique value in the runtime system, created with make_ref/0

Other Data types

These are built on top of the types above.

1. Date - year-month-day structs in a given calendar
2. DateTime - date and time with time zone in a given calendar
3. Exception - data raised from errors and unexpected scenarios
4. MapSet - unordered collections of unique elements
5. NaiveDateTime - date and time without time zone in a given calendar
6. Keyword - lists of two-element tuples, often representing optional values
7. Range - inclusive ranges between two integers
8. Regex - regular expressions
9. String - UTF-8 encoded binaries representing characters
10. Time - hour:minute:second structs in a given calendar
11. URI - representation of URIs that identify resources
12. Version - representation of versions and requirements

“Strings”

Manipulating Strings

String.split - converts string into a list with each word put in quotes, separated by a comma

"asdfasd" |> String.split

{Tuples} for fixed number of elements

{"string", integer, f.loat, :atom}

elem(variable, position_in_index) to extract values in the tuple

a = {"Lam", 143}
elem(a, 1)`
# 123

[Character List]

Denoted by ~c

?x denotes the code point of x

Binary «1, 2, 3»

Atom

An atom’s name is the same as its value

Atom
:atom_name
:Atom_name
:"Atom name"

Converting Data Types

Convert string to numbers

String.to_integer and String.to_float - converts a string-integer and string-float into an integer and float

"123" |> String.to_integer
"123.123" |> String.to_float

Integer.parse, Float.parse

123 |> Integer.parse

# returns tuple e.g. {123.45, ""}
Integer.parse(n)
Float.parse(n)

# returns integer
String.to_integer(n)
String.to_float(n)


Decimal.new(n) |> Decimal.to_integer
Decimal.new(n) |> Decimal.to_float

Example

"1.0 1 3 10 100" |> String.split |> Enum.map(fn n -> Float.parse(n) |> elem(0) end)
[1.0, 1.0, 3.0, 10.0, 100.0]

Convert numbers to string

n |> to_string([decimals: 2, compact: true])

Convert float to charlist

n |> to_charlist()

Erlang Functions

:timer

IO.puts "whatever"

Module

container for the functions

defmodule ModuleName1 do
  def function_name(argument1, argument2,..) do 
    ModuleName2.function_name()