hash_vs_class.rb

require_relative 'person'

# ARRAY CRUD

# CREATE
# index.       0.      1.    ...
musicians = ["paul", "ringo"]
p musicians

# READ
puts musicians[0].capitalize

# UPDATE

musicians[1] = "john"
p musicians

musicians << "ringo"
p musicians

# DELETE
# delete_at method receives an index
musicians.delete_at(2)
p musicians

musicians[0] = nil
p musicians

numbers = [1, 2, 4, 2, 2, 6, 3]
p numbers
numbers.delete(2)
p numbers


# HASH CRUD

# CREATE
person = { name: "rui" }
p person

# READ
           # string
puts "Hi, #{person[:name].capitalize}"

# UPDATE
person[:name] = "john"
p person

# creating a new key/value pair
person[:country] = "Portugal"
p person


# DELETE
person.delete(:country)
p person


# CLASSES
# with hash
puts "Hi, #{person[:name].capitalize}"
rui = Person.new({name: "Rui"})
# with class

# rui is an instance of Person
puts rui.class
# i need to call it on the instance
rui.greet

# use a class method
# I need to call it on the class
puts Person.props

person.rb

class Person
  def initialize(attributes = {})
    # define instance variables
    @name = attributes[:name]
  end

  # instance variable ara available
  # across the class
  def greet # instance method
    puts "Hi, #{@name}"
  end

  def self.props # class method
    "Hi, my properties are name"
  end
end