Ruby Review & Object Oriented Programming

intro.rb

people[0][:emails][2][:a]


((5 + 3) * 8 / 9 - 2)

subtract(divide(multiply(add(5, 3), 8), 9), 2)

people = [
    {
        name: "murat",
        phone: "345345",
        handles: {
            twitter: "@poophead",
        }
        emails: ["[email protected]", "[email protected]", {a: 5}],
    },
    {
        name: "murat",
        phone: "345345",
    },
    {
        name: "murat",
        phone: "345345",
    },
]

people.each do |person|

    person.each do |key, value|
        puts "#{key}: #{value}"
    end

    if person.has_key?(:handles)
        person[:handles].each do |type, handle|
            puts "  #{type}: #{handle}"
        end
    end
end

people_with_phones = people.select do |person|
    person.has_key?(:phone)
end

people_with_phones = []
people.each do |person|
    if person.has_key?(:phone)
        people_with_phones << person
    end
end

phones = people.map do |person|
    person[:phone]
end
# ["2343245", "456456"]

oop.rb

# class, is the blueprint
# class can have methods and variables. class methods, class variables

# an instance is created from a class. a.k.a. an object.
# instances have instance variables and instance methods

# classes can inherit from previously defined classes
# they can override methods. they can reuse inherited methods (super)

# methods can be public or private (called from outside vs. only inside the class)

# getter and setters can conveniently be defined via "attr_accessor :attribute_name"

class Person
    attr_accessor :name
    @@population = 0

    def initialize(name)
        @name = name
        capitalize

        if @name != "lil jonny"
            @@population += 1
        end
    end
    
    def name=(name)
        @name = name
        capitalize
    end

    # INSTANCE method
    def capitalize
        capitalized_names = @name.split(" ").map do |subname|
            subname.capitalize
        end

        new_name = capitalized_names.join(" ")
        @name = new_name

        return new_name
    end

    # CLASS method
    def self.population
        @@population
    end
end


class Student < Person
    attr_accessor :student_id, :gender
    @@student_population = 0

    def initialize(name, gender)
        @@student_population += 1
        @gender = gender

        # also increase general population
        super(name)
    end
end

puts "population: #{Person.population}"

# person1 is an OBJECT, a.k.a an INSTANCE, of the CLASS Person
person1 = Person.new("murat ayfer")
person1.name = "ayfer murat"


puts person1.name

person2 = Person.new("khurram")
# puts person2.capitalize

student1 = Student.new("i don't know your names yet", "male")
student1.student_id = 384583745
puts student1.inspect

puts "population: #{Person.population}"