Elixir: Anonymous Functions - A Taste of Functional Programming

An anonymous function is composed of an optional parameter list, a body enclosed by fn -> and end. It returns a function definition and the potential for the function to be executed. Quite simply the anonymous function can be assigned to a variable which then can be subsequently called.

Define an anonymous function:,

greet = fn ->
  IO.puts "Hello World"
end

Of course that does nothing unless we call it! We can do that by using this dot notation -

[function name].([optional parameters])

Like this:

greet.()

Where the output is: Hello World

Anonymous functions with parameters

add = fn(num1, num2) ->
  num1 + num2
end

IO.puts add.(10, 15)
IO.puts add.(12, 15)
IO.puts add.(14, 19)

subtract = fn num1, num2 -> num1 - num2 end
IO.puts subtract.(15, 10)

Output:

25
27
33
5

I hope these examples ignite an interest for you to further learn functional programming using Elixir. Cheers!

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Other posts in this series:

• A Taste of Functional Programming
• Anonymous functions
• Pattern matching
• Multi-bodied functions
• Higher order functions
• Side effects and state
• Composition
• Enumerables
• Partial function applications
• Recursion
• Concurrency
• Transitioning from OOP to functional