Elixir Cheatsheet

Sample program

IO.puts "Hello, World!"

• IO.puts : To print output data to the console
• # : comment

Variables

Variables must be declared and assigned a value.

variable-name = value

Data types

Data type	Usage	Description
Numeric	x = 21	Elixir supports not only integer and float values but also a number can be defined in octal, hexadecimal and binary bases.
Atom	:true	Atoms are constant values whose name is same as their value
Boolean	: false, :true	Either true or false, usually declared as atoms
Strings	"Hello"	Strings are enclosed in double quotes(" ") and multi line strings are enclosed in triple double quotes(""" """)
Lists	['a', 10, :true]	Lists are used to store different types of values and are represented in square brackets []
Tuples	{'apple', 100, :false}	Similar to Lists and are represented in curly brackets {}. Tuples are good for accessing the values and lists are good for insertion and deletion of values

Reserved Keywords

after	and	catch	do	inbits	true
inlist	nil	else	end	not	when
or	false	fn	in	rescue	xor

Operators

Operator type	Description
Arithmetic Operator	+ , - , * , / , div, rem
comparision Operator	< , > , <= , >=, !=, !==, === , ==
Bitwise Operator	&&& , ^^^ , |||, ~~~, <<<, >>>
Boolean Operator	and , or, not, &&, ||, !

Conditional Statements

1. If

if condition do
  #Code 
end

2. If-Else

if condition do
  #Code 
else
  #code
end

3. Case

case value do
  value-1 -> #code if value matches value-1
  value-2 -> #code if value matches value-2
  value-3 -> #code if value matches value-3
  ...
  _ -> #code if value does not match any of the above and is similar to default in switch
end

Loops

1. Unless

unless condition do
  #Code 
end

2. Unless-Else

unless condition do
  #Code if condition fails
else
  #Code if condition satisfies
end

3. Cond

cond do
  condition-1 -> #code if condition is true
  condition-2 -> #code if condition is true
  ...
  true -> #code if none of the above are true
end

List

List is a collection of data of the same or different types and are stored in memory as linked lists.

["foo", 123, true]

List Functions	Description
length()	returns the length of a list
++	used to concatenate two lists by adding list items
--	used to concatenate two lists by substracting list items
hd(list)	to get the first element of the list
tl(list)	to get last element of the list
delete(list, item)	to delete an item from the list
delete_at(list, index)	to delete an item at given index from the list
insert_at(list, index, value)	to insert given item at specific index of a list

Tuples

Tuples are collection of data of the same or different types and are stored contiguously in memory.

tuple = {:foo, :bar}
Tuple.append(tuple, :john) # appends an item to tuple

Maps

Map is a collection of key-value pairs.

map = %{1 => :one, 2 => :two, 3 => :three, 4 => :four, 5 => :five}

Functions

Function is a sub-routine which contains set of statements.

1. Anonymous Functions:

Anonymous functions are functions with no name and they use fn..end constructs.

2. Named functions:

Assign names to functions so that they can be called easily. Always named functions are defined in modules.

defmodule ModuleName do
  def function_name(parameter1, parameter2) do
    #code 
  end
end