student.rb

class Student
  attr_reader :first_name, :last_name, :nationality, :gender
  #.             first_name, last_name ...
  def initialize(params = {})
    @first_name = params[:first_name]
    @last_name = params[:last_name]
    @nationality = params[:nationality]
    @gender = params[:gender]
  end

  # this is an instance method
  # this one is called on the instance
  # def categories
  #   ["beginner", "advanced"]
  # end

  # this is a class method
  # need to be called on Student
  def self.categories
    # self => refers to the class
    puts self
    ["beginner", "advanced"]
  end

  # def first_name
  #   @first_name
  # end

  # def self.class_method
  #   self refers to the class
  # end

  def full_name
    # self refers to the instance
    # self.first_name
    puts self
    "#{@first_name.capitalize} #{@last_name.capitalize}"
  end

  def to_array
    [@first_name, @last_name, @nationality, @gender]
  end
end

students.csv

students.rb

# used for ruby library
# or gems
require 'csv'
# require_relative
# used for local files
require_relative 'student'


filepath = './students.csv'
csv_options = {
  headers: :first_row,
  header_converters: :symbol,
  col_sep: ','
}


# PARSING
#       permanent  -> ephemeral
# physical storage -> computer memory
students = []
CSV.foreach(filepath, csv_options) do |row|
  # puts "#{row[:first_name].capitalize} #{row[:last_name].capitalize} is a #{row[:nationality].capitalize} #{row[:gender]}."
  student_hash = {
    first_name: row[:first_name],
    last_name: row[:last_name],
    nationality: row[:nationality],
    gender: row[:gender]
  }
  students << Student.new(student_hash)
end
p students

puts "What's your name?"
name = gets.chomp.downcase.split
first_name = name[0]
second_name = name[1]

puts "What's your nationality?"
nationality = gets.chomp.downcase

puts "What's your gender?"
gender = gets.chomp.downcase

student_hash = {
  first_name: first_name,
  last_name: last_name,
  nationality: nationality,
  gender: gender
}

students << Student.new(student_hash)

# STORING
# computer memory -> physical storage
CSV.open(filepath, 'wb', csv_options) do |csv|
  # we need to write the headers
  # csv << write one row at a time
  csv << [:first_name, :last_name, :nationality, :gender]
  students.each do |student|
    # gets executes the number of students times
    csv << student.to_array
  end
end

task.rb

class Task
  attr_reader :description
  # this one only runs once .new
  def initialize(description)
    @description = description
    @done = false
  end

  # def done
  #   @done
  # end

  # return either true or false
  # convention uses ?
  def done?
    @done
  end

  # it changes an atribute
  # convention ! for destructive methods
  def mark_as_done!
    @done = true
  end
end

# ternary operator
# task.done? => is either true or false?
# task.done? ? "[x]" : "[ ]