Random Ruby Tricks & Info

Eighth article in the Prepare for a Ruby job interview series. In this article, we will go over some random Ruby tricks and information.

The 4 ways to call a method

  object = Object.new
  object.object_id

--

  object.send('object_id')

--

  object.send(:object_id)

--

  object.method(:object_id).call

Symbol vs String

Symbols are unique immutable entities as opposed to string which are mutable.

  :fu.object_id # 522248
  :fu.object_id # 522248
  'fu'.object_id # 70139185894080
  'fu'.object_id # 70139182497200

As you can see, the :fu symbol is always the same but the 'fu' string changes. Symbols are more memory efficient so don't hesitate to use them

Global Variable

I don't recommend using global variables but you should be able to recognize them. Actually, you just have to add dollar sign, it will remind you of PHP yay !

$fu = 'fu' # That's a global variable. But don't do it.

What is Self

Self gives you the current object, be it a class, or anything else.

The ||= operator

This operator is super useful to initialize variable when they might already hold data.

a ||= b

is the equivalent of :

a || a = b

If you define a method at the top level scope, it goes to Object

  def yo
    p 'yo'
  end

  Object.yo
  # => 'yo'

One liner method declaration

  def greet; puts "hello"; end
  def hello() :hello end

Checkout the next article about the FizzBuzz and Fibonacci algorithms.